Tetra (4-carboxyphenyl) porphyrin (TCPP) was loaded on the surface of Pt/g-C3N4 via a simple adsorption process, and the microstructure and chemical structure of the composites were characterized by high resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV–visible diffused reflectance spectroscopy and photoluminescence spectroscopy. Loading TCPP onto Pt/g-C3N4 enhanced the visible-light-driven photocatalytic evolution of H2 from water. The TCPP/Pt/g-C3N4 composite with a TCPP loading of 1 wt% had the highest photoactivity, which was 2.1 times higher than that of Pt/g-C3N4. This improvement is attributed to enhanced visible light utilization by the TCPP/Pt/g-C3N4 resulting from the strong visible light response of TCPP. In addition, the formed organic heterostructure between TCPP and g-C3N4 with overlapping bad gaps accelerates the electron transfer and inhibits the recombination of the photogenerated electrons and holes on g-C3N4.Download high-res image (246KB)Download full-size image

Five tolyl-functionalized monophosphine substituted diiron complexes [Fe2(CO)5(L){μ-SC6H3(CH3)S}] (L = PPh3, 2; Ph2PCH2Ph, 3; Ph2PCH2CH2CH3, 4; Ph2P(2-C5H4N), 5; P(4-C6H4OCH3)3, 6), which could be regarded as the active site models of [FeFe]-hydrogenases, have been successfully synthesized from parent complex [Fe2(CO)6{μ-SC6H3(CH3)S}] (1). The influence of the different phosphine ligands on the reduction potentials of the models has been evaluated by cyclic voltammetry (CV). According to the result of the electrochemical analysis, complexes 1, 2 and 5 were chosen to carry out the photocatalytic experiments. Meanwhile, tetraphenylporphyrin (TPP) covalently functionalized graphene oxide (GO) nanocomposite (TPP-GO) and cystine were applied as the photosensitizer and the electron-donor respectively in the [FeFe]-hydrogenases bionic photocatalytic system. The result of light-driven hydrogen (H2) evolution in aqueous ethanol solution demonstrated that the efficiency of H2 production is affected by following factors: the participation of GO or cystine, the covalent functionalization of GO by TPP and the hetero-atom on the phosphine ligand substituent of [FeFe]-hydrogenases models. Ultraviolet-visible (UV–vis) absorption, fluorescence emission and time-resolved fluorescence were used to analyze and compare the efficiency of electron transferring in the process of photocatalytic H2 production. And a possible mechanism for the light-driven H2 evolution of the photocatalytic system containing TPP-GO was proposed.

In this study, a binary composite polypyrrole@MnMoO4 was facilely prepared via in situ oxidative polymerization of monomer in the presence of MnMoO4 nanorods The MnMoO4 nanorods were wrapped by a layer of polypyrrole (PPy) and formed a core-sheath structure which embedded in PPy matrix. The prepared PPy@MnMoO4 composite was characterized by XRD, IR, SEM, and TEM spectroscopy and its capacitive performance was investigated. Electrochemical measurements show that the specific capacitance of PPy@MnMoO4 composite (MnMoO4 content is 13.95 wt%) reached 462.9 F g−1 at a scan rate of 5 mV s−1 and 374.8 F g−1 at a current density of 0.2 A g−1 in a three-electrode system. In the two-electrode system of a symmetric supercapacitor, it achieved specific capacitances of about 221.3 F g−1 at a scan rate of 5 mV s−1 and 207.5 F g−1 at a current density of 0.5 A g−1. The PPy@MnMoO4 retained 80.6% of its initial capacitance after 1000 cycles. The excellent electrochemical performance of PPy@MnMoO4 composite is attributed to the synergistic effects between the polymer chain and MnMoO4 in PPy@MnMoO4 and its well-designed structure.

Reactions of [Co(dmgH)(dmgH2)Cl2] (dmgH = dimethylglyoxime) or [Co(chdH)(chdH2)Cl2] (chd = 1,2-cyclohexanedione dioximate) with 4,4′-bipyridine in MeOH in the presence of Et3N resulted in the formation of binuclear cobaloxime complexes [{Co(dmgH)2Cl}2(bipy)] (1, bipy = 4,4′-bipyridine) and [{Co(chdH)2Cl}2(bipy)] (2) in good yields. Complexes 1 and 2 were characterized by NMR and X-ray crystallography. Both 1 and 2 were found to be molecular catalysts for light-driven hydrogen evolution in the presence of Eosin Y as photosensitizer and triethanolamine as sacrificial electron donor in aqueous acetonitrile solutions upon irradiation.

A polyacrylamide inverse-opal hydrogel (IOHPAM) film was synthesized by in situ polymerization in a polystyrene colloidal crystal template. The IOHPAM has a periodically ordered interconnecting porosity that endows the film with a band gap and structural color. The IOHPAM film exhibits a rapid reversible change in volume and in refractive index in response to alcohols and, consequently, the structural color and reflection peak of the IOHPAM film are quickly synchronized with these changes. The reflection peak of the IOHPAM film shows obvious blue or red-shifts that depend on the structure of the alcohols. The extent of the shift not only depends on the number of –OH groups, but also on the chain length, structure and concentration of the alcohols. The IOHPAM film is also sensitive to polyethylene glycol (PEG) and displays different blue-shift responses to PEGs with different molecular weights. Since the IOHPAM films have different reflectance spectra and structural colors in response to different types and concentrations of alcohols, this provides a potential way to visually detect alcohols.

•Eight Ni chelating complexes were successfully synthesized as H2 production catalysts.•TPP covalently functionalized GO nanohybrid was introduced into the photocatalytic system.•H2 production efficiency was improved due to the participation of the GO nanohybrid.Eight nickel complexes with chelating N-substituted bis(diphenylphosphanyl)amine and 1,2-benzenedithiolate or 3,4-toluenedithiolate, [RN(PPh2)2]Ni(1,2-SC6H4S) [R = CH(CH3)2, 1; CH2CH(CH3)2, 2; CH2CH2CH2CH3, 3; CH2Ph, 4] and [RN(PPh2)2]Ni[3,4-SC6H3(CH3)S] [R = CH(CH3)2, 5; CH2CH(CH3)2, 6; CH2CH2CH2CH3, 7; CH2Ph, 8], were synthesized and structurally characterized. The measurement of the electrochemical properties revealed that complex 4 can catalyze protons to hydrogen (H2) under weak acidic conditions. Complex 4 can also be used as a molecular catalyst for light-driven H2 evolution with a proton source, a photosensitizer, and an electron donor. Furthermore, by using tetraphenylporphyrin (TPP) amide-covalently functionalized graphene oxide (GO) nanohybrid (TPP-NH-GO) as a photosensitizer, the efficiency of photocatalytic H2 production of complex 4 in aqueous ethanol solution had been astonishingly improved over than for the photocatalytic systems without GO. This result suggests that the excellent properties of GO with respect to electron transfer, surface area, adsorptivity, and hydrophilicity may promote the performance of the photocatalytic H2 production system to a certain extent.Download high-res image (114KB)Download full-size image

A polyacrylamide inverse-opal hydrogel (IOHPAM) film was synthesized by in situ polymerization in a polystyrene colloidal crystal template. The IOHPAM has a periodically ordered interconnecting porosity that endows the film with a band gap and structural color. The IOHPAM film exhibits a rapid reversible change in volume and in refractive index in response to alcohols and, consequently, the structural color and reflection peak of the IOHPAM film are quickly synchronized with these changes. The reflection peak of the IOHPAM film shows obvious blue or red-shifts that depend on the structure of the alcohols. The extent of the shift not only depends on the number of –OH groups, but also on the chain length, structure and concentration of the alcohols. The IOHPAM film is also sensitive to polyethylene glycol (PEG) and displays different blue-shift responses to PEGs with different molecular weights. Since the IOHPAM films have different reflectance spectra and structural colors in response to different types and concentrations of alcohols, this provides a potential way to visually detect alcohols.