Nanocomposites obtained by integrating iron oxide magnetic nanoparticles (Fe3O4) into a metal–organic framework (HKUST-1 or Cu3(BTC)2, BTC = 1,3,5-benzenetricarboxylate) are synthesized through conversion from a composite of a Cu-based ceramic material and Fe3O4. In situ small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) measurements reveal that the presence of Fe3O4 leads to the fast conversion and synthesis of HKUST-1 with small particle sizes. The prepared MOF composite (Fe3O4@HKUST-1) is found to catalyze the one-pot sequential deacetalization–Knoevenagel condensation reaction as a magnetically collectable and recyclable catalyst. In addition, Pd nanoparticles are also incorporated into the material (Pd/Fe3O4@HKUST-1) by addition of a Pd colloidal solution during the conversion of the precursor composite to HKUST-1. The resulting Pd/Fe3O4@HKUST-1 can be utilized for hydrogenation of 1-octene in the liquid phase.

An iron-based metal–organic framework, MIL-101(Fe), promotes photocatalytic water oxidation to produce oxygen from aqueous silver nitrate solution under visible-light irradiation. The finely dispersed iron-oxo clusters embedded as nodes of the porous framework would contribute importantly to the efficient promotion of the reaction as compared to bulk hematite (α-Fe2O3).

The present article deals with Pt complex construction within Zr-based MOF having bipyridine units in the framework (Zr-MOF-bpy-PtCl2) and its photocatalytic activity for hydrogen production under visible-light irradiation (λ > 420 nm). Zr-MOF-bpy-PtCl2 is prepared by the construction of a Zr-based MOF using 2,2′-bipyridine-5,5′-dicarboxylic acid (Zr-MOF-bpy), and subsequent complexation reaction with K2PtCl4. XRD and N2 adsorption–desorption measurements have revealed that both Zr-MOF-bpy and Zr-MOF-bpy-PtCl2 have a UiO-type structure. From the results of UV–Vis and XAFS measurements, the incorporated Pt species has been proven to be in square planar geometry involving two N atoms and two Cl atoms as a result of the Pt coordination with bipyridine units in the framework. Zr-MOF-bpy-PtCl2 has been employed for a hydrogen production reaction from water containing a sacrificial electron donor under visible-light irradiation (λ > 420 nm). Zr-MOF-bpy-PtCl2 realizes steady hydrogen production, and the amount of evolved hydrogen reaches 8.3 μmol after the 9 h reaction period, while Zr-MOF-bpy exhibits no photocatalytic activity under the same conditions. It has also been found that the activity of Zr-MOF-bpy-PtCl2 is superior to that of the corresponding homogeneous complex analogue (bpy)PtCl2.

A Zr-based metal–organic framework with tetrakis(carboxyphenyl)porphyrin groups (Zr-MOF-TCPP: MOF-525) has been utilized as a photoredox catalyst to promote oxidative hydroxylation of arylboronic acids under green LED light irradiation. Zr-MOF-TCPP displays a superior catalytic activity for this process over the corresponding homogeneous catalyst (H4TCPP).

A sequential one-pot reaction to produce organophosphorus compounds via Knoevenagel condensation and phospha-Michael addition has been realised by utilising ZIF-8 as a heterogeneous catalyst. The combination of 2-methylimidazolate anions and Zn2+ cations in ZIF-8 is revealed to be effective for the efficient promotion of the one-pot reaction.

The present article describes the development of a periodic mesoporous organosilica (PMO)-based bifunctional catalyst that includes both oxidative and base catalytic activities. Periodic mesoporous ethylenesilica (PME) was selected as a catalyst support and modified with ethylenediamine through epoxidation of bridging ethylene moieties and the following nucleophilic addition in order to construct base sites. FT-IR measurements for the resulting material, PME-ED, reveal the successful introduction of amino groups into the bridging ethylene moieties. PME-ED can promote Knoevenagel condensation between benzaldehyde and various active methylene compounds as a solid base catalyst. The scope of applicable active methylene compounds in this catalytic system shows the base strength of PME-ED, in which a proton can be abstracted from diethyl malonate (pKa: 16.4) but not from benzyl cyanide (pKa: 21.9). Moreover, the generation of bifunctional catalytic properties to promote a one-pot tandem reaction consisting of alcohol oxidation and Knoevenagel condensation is realised by loading of Au nanoparticles within PME-ED. This catalyst design methodology can be also extended to developing another bifunctional catalyst that is composed of Pd nanoparticles and PME modified with N,N-dimethylethylenediamine in order to promote a Tsuji–Trost reaction.

A catalytically competent Cu species has been immobilized within the framework of a Zr-based metal–organic framework with bipyridine units, Zr-MOF-bpy, by a simple postsynthetic modification method from CuBr2 (Zr-MOF-bpy-CuBr2) and used for the selective oxidation of cyclooctene to cyclooctene oxide. Zr-MOF-bpy was synthesized by a simple solvothermal method and was shown to have a UiO-type structure. Diffuse reflectance UV–vis and XAFS measurements have revealed that the immobilized Cu species has a square-planar geometry of two N atoms and two Br atoms. Zr-MOF-bpy-CuBr2 catalyzed the selective oxidation of cyclooctene to cyclooctene oxide with high activity and selectivity in the presence of tert-butyl hydroperoxide as an oxidant. In addition, the catalytic ability of Zr-MOF-bpy-CuBr2 was demonstrated to be superior to that of the corresponding homogeneous catalyst ((bpy)CuBr2). It was also confirmed that Zr-MOF-bpy-CuBr2 can be reused as a heterogeneous catalyst without significant loss of its activity and selectivity.

A Ru complex-incorporated Ti-based MOF (Ti-MOF-Ru(tpy)2) has been synthesised by using a bis(4′-(4-carboxyphenyl)-terpyridine)Ru(II) complex (Ru(tpy)2) as an organic linker. Ti-MOF-Ru(tpy)2 promotes photocatalytic hydrogen production from water containing a sacrificial electron donor under visible-light irradiation up to 620 nm.

A novel one-pot reaction system is developed by utilizing a bifunctional metal–organic framework photocatalyst (Zr-MOF-NH2). Zr-MOF-NH2 promotes sequential photocatalytic oxidation and Knoevenagel condensation reaction to produce benzylidenemalononitrile from benzyl alcohol and malononitrile under UV-light irradiation.

An organoruthenium complex (–[biphRuCp]PF6–; biph = –(C6H4)2–, Cp = C5H5), constructed within a biphenylene-bridged inorganic–organic hybrid mesoporous material (HMM–biph) by use of a simple ligand-exchange reaction, has been used as a heterogeneous catalyst. UV–visible and X-ray absorption fine structure (XAFS) studies furnished evidence that the structure of the complex is closely similar to that of [(C6H6)RuCp]PF6, suggesting that the biphenylene moiety within HMM–biph directly coordinates the metal center of the organoruthenium complex. The –[biphRuCp]PF6– complex constructed within the HMM–biph (HMM–biphRuCp) catalyzes hydrosilylation of 1-hexyne with triethylsilane in a solid–gas heterogeneous system and gives α-vinylsilane as a main product. Moreover, HMM–biphRuCp has higher catalytic activity than the –[phRuCp]PF6– (ph = –C6H4–) complex constructed within phenylene-bridged HMM (HMM–phRuCp). The high catalytic performance of HMM–biphRuCp can be attributed to the high loading of the HMM–biph with the Ru complex, because of the electron-donating ability of the biphenylene moieties.

Sn-containing MCM-41 (Sn-MCM-41) with different tin content was prepared by hydrothermal synthesis then treated with triflic acid to form tin triflate within the silica framework (SnOTf-MCM-41). XRD and UV–visible measurements revealed that SnOTf-MCM-41 have highly ordered mesoporous structures with tetrahedrally-coordinated Sn species. Moreover, results from FT-IR analysis revealed that triflate ligands are selectively coordinated with Sn4+ species in the mesoporous silica frameworks. SnOTf-MCM-41, as Lewis acid catalysts, promoted the Mukaiyama aldol reaction of benzaldehyde with 1-trimethylsiloxycyclohexene at room temperature and had greater catalytic activity than untreated Sn-MCM-41. Taking into account results from in situ FT-IR experiments using pyridine as probe molecule, the enhanced catalytic performance after triflic acid treatment was attributed to an increase in the number of acid sites, because of appearance of water tolerance by the formation of metal triflate species. In addition, the SnOTf-MCM-41 catalyst was reusable at least three times in the Mukaiyama aldol reaction.

Efficient hydrogen production and photocatalytic reduction of nitrobenzene were achieved by using a Pt-deposited amino-functionalised Ti(IV) metal–organic framework (Pt/Ti-MOF-NH2) under visible-light irradiation. XRD and N2 adsorption measurements revealed that crystalline microporous structures were formed and maintained even after the Pt deposition. The photocatalytic activity for the visible-light-promoted hydrogen production was improved through the optimization of the deposition amount of Pt as a cocatalyst. The optimised amount of Pt was determined to be 1.5 wt%. The results of in situ ESR measurements clearly indicate that the reaction proceeds through the electron transfer from the organic linker to deposited Pt as a cocatalyst by way of titanium-oxo clusters. In addition, the Pt/Ti-MOF-NH2 photocatalyst was found to catalyse photocatalytic reduction of nitrobenzene under visible-light irradiation. It was also confirmed that the catalyst can be reused at least three times without significant loss of its catalytic activity.

The present perspective describes recent advances in visible-light-responsive photocatalysts intended to develop novel and efficient solar energy conversion technologies, including water splitting and photofuel cells. Water splitting is recognized as one of the most promising techniques to convert solar energy as a clean and abundant energy resource into chemical energy in the form of hydrogen. In recent years, increasing concern is directed to not only the development of new photocatalytic materials but also the importance of technologies to produce hydrogen and oxygen separately. Photofuel cells can convert solar energy into electrical energy by decomposing bio-related compounds and livestock waste as fuels. The advances of photocatalysts enabling these solar energy conversion technologies have been going on since the discovery of semiconducting titanium dioxide materials and have extended to organic–inorganic hybrid materials, such as metal–organic frameworks and porous coordination polymers (MOF/PCP).

Arenetricarbonyl metal complexes ([–phM(CO)3–] and [–biphM(CO)3–]; ph = phenylene, biph = biphenylene, M = Mo, Cr) constructed within Zr-based MOFs act as highly active and selective catalysts for epoxidation of cyclooctene. Catalytic activities of these complexes are enhanced with increasing the pore sizes of Zr-based MOFs.

The amino-functionalised metal–organic framework, MIL-101(Al)-NH2, has been synthesized by using a solvothermal method and employed as a bifunctional acid–base catalyst for a one-pot, sequential deacetalization–Knoevenagel condensation reaction. In preliminary studies, the abilities of MIL-101(Al)-NH2 to serve as an acid and base catalyst were explored separately by two typical acid- and base-catalysed reaction, that is, deacetalization of benzaldehyde dimethylacetal and Knoevenagel condensation of benzaldehyde with malononitrile. MIL-101(Al)-NH2 was found to catalyse each of these reactions with high efficiency. MIL-101(Al)-NH2 was then employed as a catalyst for the one-pot sequential deacetalization–Knoevenagel condensation reaction between benzaldehyde dimethylacetal and malononitrile. Benzylidenemalononitrile as the final product was successfully generated with a high yield via benzaldehyde over MIL-101(Al)-NH2. In addition, the catalytic ability of MIL-101(Al)-NH2 was demonstrated to be superior to those of conventional heterogeneous, homogeneous as well as other functionalised metal–organic framework catalysts. Finally, the results show that MIL-101(Al)-NH2 can be reused as a catalyst for this process without significant loss of its activity.

Visible light-responsive TiO2 (Vis-TiO2) electrode has been applied for the Pt-free separate-type photofuel cell (SPFC) where two different electrolytes containing various biomass derivatives and a I3−/I− redox solution were employed for the anode and cathode sides, respectively. This new SPFC exhibits good photoelectrochemical performance under simulated solar-light irradiation. It was found that the Rh3+ loading on Vis-TiO2 electrode enhanced the photoelectrochemical performance of the SPFC through the increase in the visible light absorption as well as the increase in the electron conductivity of Vis-TiO2 electrode.

Visible light-responsive TiO2 (Vis-TiO2) thin films were successfully developed by applying a radio-frequency magnetron sputtering deposition method by controlling various sputtering parameters such as the substrate temperature, Ar gas pressure, and the target-to-substrate distance. UV–Vis, XRD and SEM investigations revealed that optical property, the crystal structure, and photocatalytic activity of Vis-TiO2 are strongly affected by the sputtering parameters during the deposition step. Vis-TiO2 was found to act as an efficient photocatalyst for the H2 and O2 evolution from water under visible light irradiation (λ ≥ 420 nm). SIMS investigations have revealed that a slight decrease in the O/Ti ratio of the TiO2 thin films plays an important role in the modification of the electronic properties of Vis-TiO2 thin films, enabling them to absorb visible light.

Development of efficient Pt-free photofuel cells employing two different electrolytes containing various biomass derivatives and an I3−/I− redox solution for the anode and cathode sides, respectively, is described. These new, separate-type photofuel cells exhibit good photoelectrochemical performance under simulated solar-light irradiation.

Visible light-responsive TiO2 (Vis-TiO2) thin films able to absorb UV and visible light in wavelength regions of 250–600 nm were successfully developed by applying a radio-frequency magnetron sputtering deposition method. These Vis-TiO2 thin films exhibited high activity for the photocatalytic oxidation of 2-propanol diluted in water even under visible light irradiation (λ ≥ 450 nm). The photocatalytic activity of Vis-TiO2 thin films was dramatically enhanced by the deposition of Pt particles on the surface. Secondary ion mass spectrometry measurements revealed that Pt particles are distributed from the top surface to the deep bulk of Vis-TiO2 thin films with a columnar structure. The unique columnar structure of Vis-TiO2 thin films plays an important role in the high photocatalytic performance.

Inorganic–organic hybrid mesoporous material incorporating organoruthenium complexes within its organosilica frameworks (HMM–phRuCpPF6) has been successfully prepared by a ligand exchange reaction. HMM–phRuCpPF6 acts as a unique heterogeneous catalyst for hydrosilylation of 1-hexyne to produce α-vinylsilane at elevated temperatures.

Visible light-responsive TiO2 (Vis-TiO2) thin film has been deposited on two different kinds of anodized Ti-metal substrates, i.e., plate-type Titanystar (P-Titanystar) or non-woven fabric Titanystar (N-Titanystar) by a radio-frequency magnetron sputtering (RF-MS) method. These Vis-TiO2 thin film photocatalysts (Vis-TiO2/P-Titanystar and Vis-TiO2/N-Titanystar) showed high activity for the oxidation of 2-propanol in water under UV light irradiation while Vis-TiO2/N-Titanystar showed higher activity than Vis-TiO2/P-Titanystar. Furthermore, photocatalytic activity of Vis-TiO2/N-Titanystar was enhanced by the Pt deposition by an RF-MS deposition method. Pt loaded Vis-TiO2/N-Titanystar (Pt-Vis-TiO2/N-Titanystar) acted as an efficient photocatalyst for the oxidation of methanol vapor under UV light irradiation even in a flow system. Moreover, it was found that Pt-Vis-TiO2/N-Titanystar is an effective photocatalyst for the oxidation of various organic compounds in gas phase or ammonia gas even under visible light irradiation (λ > 420 nm) at 293 K.

A unique photoelectrochemical circuit system was constructed by connecting a rod-type TiO2 electrode with a Pt electrode through a silicon solar cell. The photoelectrochemical circuit system efficiently oxidized ethanethiol in water into CO2, while the reaction rate strongly depended on the calcination temperature of the rod-type TiO2 electrode. Furthermore, it was found that a negative bias applied to the rod-type TiO2 electrode by a silicon solar cell enhances the oxidation rate of ethanethiol in water.

The photocatalytic preferential oxidation of CO with O2 in the presence of H2 (photo-PROX) was found to proceed efficiently on the NiO-loaded TiO2 (NiO/TiO2) catalyst under UV light irradiation at 293 K. NiO/TiO2 exhibited higher CO conversion as well as CO2 selectivity for a photo-PROX reaction than the original unloaded TiO2 (P-25). Various spectroscopic investigations have revealed that the small NiO clusters formed on TiO2 play an important role in the enhancement of CO oxidation activity in this reaction.

A highly dispersed Cr6+-oxide species on silica (Cr/SiO2) was found to act as an efficient photocatalyst for the selective oxidation of CO into CO2 with O2 in the presence of H2 under visible (λ>420 nm) or solar light irradiation at 293 K. UV-Vis, photoluminescence and FT-IR investigations revealed that the selective reactivity of the photoexcited tetrahedral Cr6+-oxide species ([Cr5+−O−]*) with CO, as well as the high reactivity of the photoreduced Cr6+-oxide species (Cr4+-oxide species) with O2 both play significant roles in this reaction.

The effect of chemical etching by HF solution on the photoelectrochemical performance and photocatalytic activity of visible light-responsive TiO2 (Vis-TiO2) thin films prepared by a radio-frequency magnetron sputtering method has been investigated. It was found that Vis-TiO2 thin films treated with HF solution (HF-Vis-TiO2) exhibit a remarkable enhancement of the photoelectrochemical performance not only under UV but also visible light irradiation as compared to untreated Vis-TiO2. The incident photon to current conversion efficiencies reached 66 and 9.4% under UV (λ = 360 nm) and visible light (λ = 420 nm), respectively. The HF-Vis-TiO2 thin films have a larger surface area and higher donor density than Vis-TiO2, indicating that the remarkable increase in the photocurrent may be due to the short diffusion length of the photoformed holes in reaching the solid–liquid interface as well as to the high conductivity. Moreover, the HF-Vis-TiO2 thin films were found to act as efficient photocatalysts for the decomposition of water with the separate evolution of H2 and O2 from H2O under visible or sunlight irradiation.

Photocatalytic reduction of NO with CO has been carried out using various single-site photocatalysts under UV-light irradiation. The single-site photocatalysts prepared by incorporating transition metal oxides within SiO2 (M/SiO2: MMo, V, and Cr) display different photocatalytic activities. Mo/SiO2 promotes photocatalytic reduction of NO with CO efficiently to produce N2 via the intermediate N2O. V/SiO2 was observed to promote the reaction that leads to selective production of N2O that does not undergo subsequent reduction to form N2. When Cr/SiO2 is used as the photocatalyst, reduction of NO does not take place. The results of Fourier transform infrared investigations reveal that differences in photocatalytic activities are due to different reactivity of reactants-adsorbed transition metal oxides in M/SiO2 and, consequently, the reaction mechanisms for the photocatalytic reduction of NO with CO over M/SiO2 are proposed.Graphical abstractThe photocatalytic reduction of NO with CO over Mo/SiO2 proceeds efficiently to produce N2 via N2O as an intermediate product. V/SiO2 promotes the NO reduction reaction, leading to the selective production of N2O without accompanying any further reduction of N2O into N2. When Cr/SiO2 is used as a photocatalyst, reduction of NO does not take place.Download high-res image (48KB)Download full-size imageHighlights► Various single-site photocatalysts were prepared by a facile impregnation method. ► The local structures of various single-site photocatalysts were investigated. ► Photocatalytic reduction of NO with CO was investigated under UV-light irradiation. ► The reaction mechanisms are described on the basis of FT-IR studies.

TixSiBEA (x = 1.5, 3.2 and 5.8 Ti wt.%) zeolites were prepared by a two-step postsynthesis method reported earlier (Chem. Commun. 1998, 87). Diffuse reflectance (DR) UV–vis and photoluminescence data suggest that mainly isolated tetrahedral framework Ti ions are present in Ti1.5SiBEA and Ti3.2SiBEA zeolites. These ions which in their excited triplet state easily interact with CO molecules as shown by photoluminescence data, are believed to be the active sites of the photocatalytic liquid phase oxidation of 2-propanol by dissolved oxygen and of photocatalytic gas phase oxidation of CO by N2O as suggested by catalytic measurements.Download full-size imageHighlights► Isolated tetrahedral framework Ti species mainly present in TiSiBEA zeolites. ► These Ti species in their excited triplet state are active sites of the photocatalytic oxidation of 2-propanol and CO. ► Photocatalytic activity of TiSiBEA depends on Ti content and is related to the amount of tetrahedral and octahedral Ti(IV).

The effect of the hydrothermal treatment with aqueous NaOH solution on the photoelectrochemical and photocatalytic properties of visible light-responsive TiO2 thin films prepared on Ti foil substrate (Vis-TiO2/Ti) by a radio-frequency magnetron sputtering (RF-MS) deposition method has been investigated. The hydrothermally treated Vis-TiO2/Ti electrodes exhibited a significant increase in their photocurrent under UV and visible light irradiation as compared to untreated Vis-TiO2/Ti electrode. SEM investigations revealed that the surface morphology of Vis-TiO2/Ti are drastically changed from the assembly of the TiO2 crystallites to the stacking of nanowires with diameters of 30–50 nm with increasing hydrothermal treatment time (3–24 h), accompanying the increase in their surface area. The separate evolution of H2 and O2 from water under solar light irradiation was successfully achieved using the Vis-TiO2/Ti/Pt which is hydrothermally treated for 5 h, while the H2 evolution ratio was 15 μmol h−1 in the early initial stage, corresponding to a solar energy conversion efficiency of 0.23%.

Highly dispersed Mo6+-oxide catalysts were supported onto various oxides (SiO2, Al2O3, and SiO2–Al2O3) by an impregnation method and their photocatalytic reactivities were investigated for the decomposition of NO with CO as well as the preferential oxidation of CO with O2 in the presence of excess H2 (photo-PROX). Mo/SiO2 was found to show the highest photocatalytic activity for these reactions. UV–vis and XAFS investigations revealed that isolated tetrahedral Mo6+-oxide species are the main Mo-oxide moieties on these catalysts. Furthermore, the distortion of the coordination sphere of tetrahedral Mo6+-oxide species was observed to increase in the following order: Mo/Al2O3 < Mo/SiO2–Al2O3 < Mo/SiO2, showing that the distorted tetrahedral Mo6+-oxide species having two short MoO double bonds is the active species for these reactions. Photoluminescence and FT-IR investigations indicated that the photo-exited Mo6+-oxide species (Mo5+–O−)* efficiently reacted with CO to form CO2 and the Mo4+-carbonyl species which is easily re-oxidized into the original Mo6+-oxide species (Mo6+O2−) through reactions with NO, N2O and O2 under dark conditions. Such unique redox properties of the Mo6+-oxide species were found to play a significant role in the photocatalytic reactions.

A Cu-based metal–organic framework (HKUST-1 or Cu3(BTC)2, BTC = 1,3,5-benzene tricarboxylate) has been synthesized from insoluble Cu-based precursors and positioned on substrates. Patterning of HKUST-1 was achieved through a two-step process: (1) the positioning of the insoluble Cu-based ceramic precursors on substrates using a sol–gel solution, and (2) the subsequent conversion into HKUST-1 by treatments with an alcoholic solution containing 1,3,5-benzene tricarboxylic acid (H3BTC) at room temperature for 10 min. This technique has been found to be suitable for both inorganic and polymeric substrates. The HKUST-1 pattern on a polymer film can be easily bent without affecting the positioned MOFs crystals. This approach would allow for versatile and practical applications of MOFs in multifunctional platforms where the positioning of MOFs is required.

A Zr-based metal–organic framework with tetrakis(carboxyphenyl)porphyrin groups (Zr-MOF-TCPP: MOF-525) has been utilized as a photoredox catalyst to promote oxidative hydroxylation of arylboronic acids under green LED light irradiation. Zr-MOF-TCPP displays a superior catalytic activity for this process over the corresponding homogeneous catalyst (H4TCPP).

Arenetricarbonyl metal complexes ([–phM(CO)3–] and [–biphM(CO)3–]; ph = phenylene, biph = biphenylene, M = Mo, Cr) constructed within Zr-based MOFs act as highly active and selective catalysts for epoxidation of cyclooctene. Catalytic activities of these complexes are enhanced with increasing the pore sizes of Zr-based MOFs.

The present perspective describes recent advances in visible-light-responsive photocatalysts intended to develop novel and efficient solar energy conversion technologies, including water splitting and photofuel cells. Water splitting is recognized as one of the most promising techniques to convert solar energy as a clean and abundant energy resource into chemical energy in the form of hydrogen. In recent years, increasing concern is directed to not only the development of new photocatalytic materials but also the importance of technologies to produce hydrogen and oxygen separately. Photofuel cells can convert solar energy into electrical energy by decomposing bio-related compounds and livestock waste as fuels. The advances of photocatalysts enabling these solar energy conversion technologies have been going on since the discovery of semiconducting titanium dioxide materials and have extended to organic–inorganic hybrid materials, such as metal–organic frameworks and porous coordination polymers (MOF/PCP).

Inorganic–organic hybrid mesoporous material incorporating organoruthenium complexes within its organosilica frameworks (HMM–phRuCpPF6) has been successfully prepared by a ligand exchange reaction. HMM–phRuCpPF6 acts as a unique heterogeneous catalyst for hydrosilylation of 1-hexyne to produce α-vinylsilane at elevated temperatures.

Efficient hydrogen production and photocatalytic reduction of nitrobenzene were achieved by using a Pt-deposited amino-functionalised Ti(IV) metal–organic framework (Pt/Ti-MOF-NH2) under visible-light irradiation. XRD and N2 adsorption measurements revealed that crystalline microporous structures were formed and maintained even after the Pt deposition. The photocatalytic activity for the visible-light-promoted hydrogen production was improved through the optimization of the deposition amount of Pt as a cocatalyst. The optimised amount of Pt was determined to be 1.5 wt%. The results of in situ ESR measurements clearly indicate that the reaction proceeds through the electron transfer from the organic linker to deposited Pt as a cocatalyst by way of titanium-oxo clusters. In addition, the Pt/Ti-MOF-NH2 photocatalyst was found to catalyse photocatalytic reduction of nitrobenzene under visible-light irradiation. It was also confirmed that the catalyst can be reused at least three times without significant loss of its catalytic activity.

A Ru complex-incorporated Ti-based MOF (Ti-MOF-Ru(tpy)2) has been synthesised by using a bis(4′-(4-carboxyphenyl)-terpyridine)Ru(II) complex (Ru(tpy)2) as an organic linker. Ti-MOF-Ru(tpy)2 promotes photocatalytic hydrogen production from water containing a sacrificial electron donor under visible-light irradiation up to 620 nm.

An iron-based metal–organic framework, MIL-101(Fe), promotes photocatalytic water oxidation to produce oxygen from aqueous silver nitrate solution under visible-light irradiation. The finely dispersed iron-oxo clusters embedded as nodes of the porous framework would contribute importantly to the efficient promotion of the reaction as compared to bulk hematite (α-Fe2O3).

A novel one-pot reaction system is developed by utilizing a bifunctional metal–organic framework photocatalyst (Zr-MOF-NH2). Zr-MOF-NH2 promotes sequential photocatalytic oxidation and Knoevenagel condensation reaction to produce benzylidenemalononitrile from benzyl alcohol and malononitrile under UV-light irradiation.