•A facile “template extracting” strategy to fabricate HPMO was presented.•PS particle is served as the sacrificial template and removed by extraction by selected solvent to obtain hollow particle.•Systematic characterizations clearly revealed that the HPMO particles have excellent monodispersity.•Multifunctional particles realize the application in magnetic separable environmental renovation and drug delivery system.A facile “template dissolving” strategy has been developed for the fabrication of hollow periodic mesoporous organosilica (HPMO) particles with perpendicularly ordered mesopores, where polystyrene (PS) is used as sacrifice template for the generation of hollow cavity. Systematic characterizations including transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and N2 adsorption/desorption analysis clearly reveal that the HPMO particles have an excellent monodispersity with a high specific surface area of 1246.7 m2 g−1, large pore volume of 1.38 cm3 g−1 and uniformly ordered mesopores of 2.48 nm. The pre-encapsulation of a core into PS (SiO2, Fe3O4@SiO2) results in a yolk-shell (Y-S) particle with high tunable shell thickness (30–60 nm) and cavity size (230–450 nm). The magnetically recyclable Fe3O4-YS-PMO was further utilized to adsorb 2, 4-dichlorophenol (2, 4-DCP) and the controlled release of camptothecin (CPT). Up to 81 mg of CPT was loaded per gram of the Fe3O4-YS-PMO particles, followed with a continuously release of 76% within 5 days.

A sensitive and selective SERS sensor with easy and excellent recyclability is highly demanded because of its great potential application in complex detection environments. Here, using methylene blue (MB) as a model target, a semiconductor-based SERS substrate composed of a MoO3 nanorod core and a uniform molecule-imprinting polymethacrylic acid shell (MIP) with a thickness of 4 nm was designed and fabricated (MoO3@MIP) to achieve selective detection. The key to the successful coating of the ultrathin uniform MIP shell lies in the pretreatment of a MoO3 core with nitric acid, providing sufficient surficial hydroxyls for the anchoring of a polymer precursor. The molecule-imprinted voids for MB were formed simply via light irradiation as a result of photocatalytic degradation by a MoO3 semiconductor. This core–shell MIP composite shows a high SERS selectivity towards low-level MB in a mixed MB/CV solution. The enhanced factor (EF) is high, at 1.6 × 104. More importantly, the selective detection allows the further photocatalytic recycling of MoO3@MIP in an “aim-and-shoot” way, which well preserves the detection selectivity and sensitivity towards MB at least for 4 cycles. Based on decreased sensitivity with the increasing shell thickness (10–24 nm), a MIP-gating charge transfer mechanism is proposed to demonstrate the high EF instead of the molecule-enrichment effect. This “aim-and-shoot” strategy is expected to push forward the prosperous application of selective SERS for trace detection in versatile environments.

•The Fe3O4@void@TiO2 NPs show a remarkable performance for degrading TC.•The synergic effect between TiO2 shell and Fe3O4 core plays an important role.•The photo-Fenton-like catalyst can work under a wide pH range of 3–9.Herein, we demonstrate the yolk-shell structured Fe3O4@void@TiO2 sphere as an efficient heterogeneous catalyst for the photo-Fenton-like degradation of tetracycline (TC). The composite was synthesized by first successively coating amorphous SiO2 and TiO2 shells around a Fe3O4 core via the sol-gel strategy to form Fe3O4@SiO2@TiO2, then crystallizing TiO2 and removing SiO2 through calcination and the ultrasonic ammonia-etching treatment, respectively. The particles are monodisperse and uniform in size (ca. 180 nm), where the diameter of the core is ca. 100 nm and the thickness of the shell is ca. 10 nm. This composite possesses anatase TiO2 shell with high crystallinity, superparamagnetic core with a saturation magnetization value of 28.71 emu/g and high specific surface area of 101 m2 g−1. It shows extremely high activity towards the degradation of TC (40 mg/L) in a wide pH range as demonstrated by almost 100% elimination efficiency at pH = 3 and ca. 75% at pH = 9 within 6 min. Moreover, benefitting from the superparamagnetism of the core, this composite could be magnetically recovered and reapplied in the TC degradation without significant loss of activity after 5 recycling (ca. 10%). The degradation curve can be well fitted by pseudo-first order model, where a kinetic constant of 0.51 min−1 is achieved, much higher than those of Fe3O4@TiO2 (0.24 min−1), hollow TiO2 (0.17 min−1), Fe3O4@SiO2@TiO2 (0.14 min−1) and Fe3O4 (0.11 min−1). The high activity is attributed to the efficient enrichment and confinement of reactants (TC and hydroxyl radicals) in the nanocavity of the yolk-shell structure, and the efficient reduction of Fe3+ to Fe2+ by the photo-generated electrons from the TiO2 shell.Yolk-shell structured Fe3O4@void@TiO2asaphoto-Fenton-likecatalystshowsanexcellentperformanceforthedegradationofTC.Download high-res image (223KB)Download full-size image

AbstractBi2WO6 was modified with MnOx via a photodeposition method. Multiple techniques including XRD, SEM, TEM, UV–vis and XPS were applied to investigate the structures, morphologies and optical characteristics of the as-prepared sample. The nanostructured composites were formed with MnOx loaded on the surface of flower-like Bi2WO6, where MnOx exists as a mixed-valence manganese of Mn3+ and Mn4+ as verified by XPS. The photocatalytic activity of the MnOx/Bi2WO6 composites was evaluated by using rhodamine B (RhB) as a target organic pollutant under visible light irradiation. The as-prepared MnOx/Bi2WO6 composites exhibited much higher photocatalytic activities than pure Bi2WO6. The enhanced activities were attributed to the interfacial transfer of photogenerated holes from Bi2WO6 to MnOx, leading to effective way to improve photocatalytic efficiency, which may be extended to a strategy for other semiconductor. Based on the experimental results, a possible mechanism of MnOx for the enhancement of visible light performance was proposed.

Yolk–shell (Y–S) structured Fe3O4@void@CdS nanoparticles (NPs) are synthesized through a one-pot coating-etching process with Fe3O4@SiO2 as the core, where the coating of an outer CdS shell from a chemical bath deposition (CBD) process is simultaneously accompanied by the gradual etching of an inner SiO2 shell. The as-prepared Fe3O4@void@CdS NPs (ca. 200 nm) possess good monodispersity and a uniform CdS shell of ca.15 nm. This composite exhibits excellent photo-Fenton (ph-F) activity toward the degradation of methylene blue (MB) in a wide pH working range of 4.5–11 under the visible light irradiation. A series of control experiments demonstrate the unique Y–S structure contributes to the enhanced activity, where the separation of hole–electron pair from CdS and the reduction of Fe2+ from Fe3+ are mutually promoted. The similar efficiency can also be achieved when the shell component changes to TiO2 or CeO2, demonstrating a general strategy for the design of robust ph-F agent.Keywords: Fe3O4@void@CdS; photo-Fenton; semiconductors; wide pH range; yolk−shell

The Stöber process is revisited using vinyltriethoxysilane as the precursor, where a kinetics-controlled condensation of vinylsilanols, free from external fluorogens, unprecedentedly produces hydrophilic diamond-structured organosilica nanocrystals (ca. 2–6 nm) with finely tunable fluorescence (460–625 nm). The key to the synthesis lies in a slow successful condensation of vinylsilanols triggered and guided by the π–π stacking interaction of vinyl groups.

Plasmonic MoO3−x@MoO3 nanosheets obtained from surface oxidation of MoO3−x were employed as a SERS substrate for methylene blue detection. They exhibit extraordinary sensitivity comparable to noble metals, which is attributed to shell-isolated electromagnetic enhancing by the plasmonic MoO3−x core and elimination of the photocatalytic degradation by the MoO3 shell.

The rational design and controlled synthesis of a smart device with flexibly tailored response ability is all along desirable for bioapplication but long remains a considerable challenge. Here, a pH-stimulated valve system with a visualized “on–off” mode is constructed through a dual-shell fluorescence resonance energy transfer (FRET) strategy. The dual shells refer to carbon dots and fluorescent molecules embedded polymethacrylic acid (F-PMAA) layers successively coating around a SiO2 core (ca. 120 nm), which play the roles as energy donor and acceptor, respectively. The total thickness of the dual-shell in the solid composite is ca. 10 nm. The priorities of this dual-shell FRET nanovalve stem from three facts: (1) the thin shell allows the formation of efficient FRET system without chemical bonding between energy donor and acceptor; (2) the maximum emission wavelength of CD layer is tunable in the range of 400–600 nm, thus providing a flexible energy donor for a wide variety of energy acceptors; (3) the outer F-PMAA shell with a pH-sensitive swelling–shrinking (on–off) behavior functions as a valve for regulating the FRET process. As such, a sensitive and stable pH ratiometric sensor with a working pH range of 3–6 has been built by simply encapsulating pH-responsive fluorescein isothiocyanate (FITC) into PMAA; a pH-dependent swelling–shrinking shuttle carrier with a finely controllable molecule-release behavior has been further fabricated using rhodamine B isothiocyanate (RBITC) as the energy donor and model guest molecule. Significantly, the controlled releasing process is visually self-monitorable.

•Carbon dot and Ti were introduced into mesoporous silica synchronously.•The mesoporous composite possesses ordered mesopores and large surface area.•The mesoporous composite has wide range of light absorption from UV to near IR range.•The co-incorporation promotes the separation and transfer of photo-induced charges.•Greatly enhanced photocatalytic activity was achieved.Carbon dots (CD) and Ti species were assembled in the mesoporous silica matrix by a one-pot co-condensation strategy. The CD and Ti in the silica matrix were demonstrated to interact in two ways: on the one hand, part of the carbon in CD was doped into the Ti species; on the other hand, CD worked as photosensitizers for Ti species. The synergy effect between CD and Ti in the silica matrix along with the unique physical properties of the composite including ordered pore channels, large surface area and wide-range light absorption from UV to near IR made this composite be an excellent photocatalyst, as demonstrated by the photocatalytic degradation of azo dye acid orange 7. In addition to the degradation of organic pollutant, this newly developed mesoporous composite is expected to have promising applications in various areas related to environment and energy such as photoreduction of CO2 and photocatalytic H2 production.

In this study, hierarchical TiO2 with macro- and mesostructure is prepared and applied in dye-sensitized solar cell (DSSCs). To achieve the hierarchical structure, hard and soft templating is combined. Polystyrene spheres serve as the hard template for μm-scale macropores, and triblock copolymers act as the soft template of nm-scale mesopores. The prepared hierarchical TiO2 is analyzed by TEM, XRD and N2 sorption, and results indicate that meso/macroporous structure is successfully obtained. Mesoporous structure provides a larger surface area for dye adsorption, and macroporous structure induces a faster electron transportation property. Combining the advantages of mesopores and macropores, the prepared hierarchical TiO2 DSSCs show a higher photon to electron efficiency in comparison to individual mesoporous and macroporous samples.

A chelating-assistant growth route of CdS on the surface of Fe3O4@SiO2 nanoparticles (NPs) was used to form a magnetically recoverable photocatalyst. Characterization by transmission electron microscopy, X-ray powder diffraction, Raman spectroscopy and a vibrating sample magnetometer reveals monodispersed superparamagnetic Fe3O4@SiO2@CdS NPs (ca. 250 nm) have been formed with a uniform CdS shell thickness of ca. 20 nm, Brunauer–Emmett–Teller (BET) surface area of ca. 25.1 m2 g−1 and saturation magnetization of 22.02 emu g−1. This composite shows excellent photocatalytic activity towards the degradation of methylene blue (MB) under visible-light irradiation with a reaction constant of 1.95 × 10−2 min−1 in spite of the low weight percentage of CdS (9.15%) as determined by the energy-dispersive X-ray spectroscopy, which is higher than those observed on Fe3O4@CdS (53.30%, 1.22 × 10−2 min−1) and CdS NPs (3.33 × 10−3 min−1). Furthermore, Fe3O4@SiO2@CdS can be quickly magnetically recovered within 30 s by applying an external magnetic field near the solution after the photocatalytic process, which still preserves the excellent particle monodispersity with the slightly reduced CdS thickness (ca. 15 nm), while Fe3O4@CdS and CdS NPs are severely photo-corroded and aggregated. The maximized specific surface area from uniform coating and the efficient generation of activated oxygen species from CdS shells might be responsible for the enhanced photoactivity.

•A fluorescent resonance energy transfer (FRET) system was built for ratiometric sensing of Hg2+ using periodic mesoporous organosilica (PMO) nanoparticles as the scaffold.•Bis-silylated anthracene (Anth) and silylated Rhodamine 6G derivative containing spirolactam unit (R6G) were adopted as the energy donor and acceptor of FRET, which were arranged into the pore framework and channel, respectively.A fluorescent resonance energy transfer (FRET) system was built for ratiometric sensing of Hg2+ in water with periodic mesoporous organosilica (PMO) nanoparticles (NPs) as the scaffold. The silylated rhodamine 6G with a spiro-ring (R6G) as the energy acceptor was covalently attached on the pore walls of anthracene (Anth) encapsulated PMO NPs, which played the role of energy donor. In the presence of Hg2+, the fluorescence emission from R6G in the pore channel was observed by exciting Anth in the framework, which means the emission energy of Anth can effectively funnel into R6G and excite it. The successful FRET from Anth to R6G should be attributed to the shortened distance between them attributed to the nanometer-sized pore system of PMO matrix, which finally leads to the emission of original colorless R6G through a Hg2+-promoted ring-opening process of R6G derivative. An extremely low detection limit for Hg2+ (6 × 10−9 M) can be achieved. These results demonstrate that fluorescent PMOs have great potential as supporting materials for enhanced fluorescence chemosensors.

A mesoporous shell containing a fluorescence resonance energy transfer (FRET) type of ratiometric Cu2+ fluorescent sensor was coated around a cetyltrimethylammonium bromide (CTAB) stabilized Fe3O4@SiO2 core. All of the units comprising the sensor composite, including the Cu2+ ligand, signal reference and reporter units, are independent of each other and without a direct covalent linkage between them, and are site-selectively self-assembled into the pore framework or channel of the mesoporous silica matrix through the electrostatic interaction between CTAB porogen and silicates. The coordination of Cu2+ and its ligand leads to the variation of fluorescence energy transfer efficiency between neighboring FRET pairs benefiting from the nanosized pore system of the mesoporous matrix, which finally results in the ratiometric detection of Cu2+. Investigation of Cu2+ adsorption performance indicated rapid removal efficiency, with a maximum adsorption capacity of 17.86 mg g−1. Fe3O4 nanoparticles were introduced as a core to make the sensor system magnetically recyclable after sensing and adsorption. Finally, the disassembly and reassembly of the Cu2+ sensor were achieved by extracting and reintroducing the units in CTAB micelles, making the sensing system reproducible.

Ag nanowires confined in mesoporous SBA-15 show improved SERS activity towards organics detection compared with Ag nanospheres. The mild chemical transformation reaction between Ag and AgCl and photocatalytic elimination of analyte were utilized to recycle the SERS detection.

Monodisperse and nanometer-sized periodic mesoporous organosilicas co-doped with fluorescence resonance energy transfer cascades composed of triple fluorophores at various ratios were prepared. These nanoparticles exhibit multifluorescent emissions by a single-wavelength excitation and were designed for the application as multichannelly traceable drug carriers. Different from the hydrophilic framework of inorganic mesoporous silica and hydrophobic framework of mesoporous carbon, these multifluorescent nanoparticles have intrinsically different and finely tunable pore surface polarities governed by the type and amount of fluorophore inside the framework. When applied as drug carriers, they can achieve synchronous or asynchronous release of different drugs by simply choosing different colored nanoparticles. These colorful mesoporous composites with finely tunable color-related drug release performance provide a strong barcoding system for the potential applications of fluorescent nanoparticles in effective screening of drugs and therapeutic protocols for diseases.

Monodisperse mesoporous silica nanosphere (MSN) modified with anthracene derivative, 2-(3-(triethoxysilyl) propylamino)-N-(9-anthryl methyl) acetamide (SGAAn) has been fabricated as a fluorescent sensor (SGAAn-MSN) for the detection of metal ions, which shows an exclusive selectivity to Cu2+. Compared with SGAAn, SGAAn-MSN presents a higher sensitivity to Cu2+. The loading amount of SGAAn in MSN has a great influence on the detection sensitivity of SGAAn-MSN, which varies with the local concentration and accessibility of SGAAn in the pore channel of MSN. Interference studies indicate that the addition of other metal ions such as Ag+, Cd2+ and Pb2+ has a negligible effect on the selectivity of SGAAn-MSN to Cu2+. The possible mechanism for the sensing behavior of SGAAn-MSN to Cu2+ is proposed based on the relation between fluorescence quench degree and Cu2+ concentration.Highlights► Cu2+ fluorescence sensor based on MSN was fabricated. ► The sensor has high detection sensitivity to Cu2+. ► The improved sensitivity is attributed to the high local concentration of dye molecules in MSN. ► The dye molecules loading amount has a great influence on the detection sensitivity.

Core-shell mesoporous silica nanospheres encapsulated with rhodamine 101 into the solid core and 8-aminoquinoline derivatives into the mesoporous shell were used as a ratiometric fluorescent sensor to detect metal ions, which shows a high selectivity and sensitivity to Zn2+. Concentrations as low as 5 × 10−8 M can be detected and the addition of other metal ions has a negligible influence on the fluorescence emission. Moreover, the dye-doped nanospheres show excellent photostability, no dye leaking and a good adsorption capacity to Zn2+, which make it repeatedly applicable for simultaneous heavy metal ion sensing and removal from polluted water.

A layered mesoporous SAPO-34 with particle size of about 20 μm was synthesized by using as-synthesized SBA-15 as silica source. For comparison, another three synthesis system were adopted to form SAPO-34 by using stoichiometric equivalence of calcined SBA-15, physical mixture of calcined SBA-15 and P123, and physical mixture of colloidal silica and P123 as initial reactants, respectively. The result shows that SAPO-34 can be prepared by all of the synthesis systems, however, only the sample prepared with as-synthesized SBA-15 shows mesoporous structure as revealed by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Compared with SAPO-34 prepared with conventional and the above three contrasting systems, the specific surface area of this sample is considerably improved due to the existence of mesoporous structure. For the application as the catalyst for methanol to olefins (MTO) reaction, the layered mesoporous SAPO-34 presents the longest single life among all of samples.Graphical abstractHighlights► Layered mesoporous SAPO-34 is fabricated using uncalcined SBA-15 as silica source. ► P123 in SBA-15 plays an important role for the formation of layered structure. ► The layered mesoporous SAPO-34 shows an improved selectivity to light olefins. ► The deactivation time for MTO is prolonged by using layered mesoporous SAPO-34.

A novel floral mesoporous SAPO-34 was synthesized via conventional hydrothermal method in the presence of NaF with F/Si = 0.02–0.2. X-ray diffraction (XRD) analysis shows that the crystallinity of SAPO-34 increases with the increasing F/Si ratio and reaches to the best at F/Si = 0.1. Further increasing of F/Si ratio leads to the decrease of the crystallinity and the ultimate phase transformation to SAPO-5. Scanning electron microscopy (SEM) analysis shows that the addition of NaF leads to the formation of floral SAPO-34 while the addition of other salts including NH4F, NH4Cl and NaCl leads to the formation of traditional cubic SAPO-34. N2 sorption isotherm and NH3 temperature programmed desorption (NH3-TPD) analyses indicate that floral SAPO-34 has the largest pore volume but lowest strong acidity compared with other samples with traditional cubic morphology. When applied to methanol to olefin (MTO) reactions, floral SAPO-34 shows the comparable yields of propylene and butylenes to other samples but lowest overall olefin yield, which is attributed to the synergistic effect of the largest pore volume and lowest strong acidity.Research Highlights► A floral mesoporous SAPO-34 is fabricated with the aid of NaF for MTO. ► The formation of floral structure is due to the eroding effect of fluoride ions. ► Floral SAPO-34 shows the highest selectivities for propylene and butylene in MTO.

A novel kind of monodisperse core−shell silica nanosphere composed of a fluorescent solid core and a mesoporous shell has been successfully fabricated. These nanospheres exhibit multifluorescent signals under a single-wavelength excitation as a result of the solid silica core that is doped with three kinds of dyes and that can produce effective fluorescence resonance energy transfer. The fluorescent signal of a single nanosphere is about 700 times brighter than its constituent fluorophores. X-ray diffraction, transmission electron microscopy, and N2 adsorption−desorption isotherms reveal that these nanospheres possess abundant mesopores in the shell. Combining the advantages of extremely bright multifluorescent signals excited with a single wavelength and an abundant mesoporous system, this core−shell silica nanosphere is designed for the simultaneous monitoring of fluorescence of in vivo multiple-target drug transport. Experiments on drug loading and release in addition to studies on cell uptake reveal that these nanospheres not only show good drug storage and sustained release capacity but also demonstrate biocompatibility and mutlifluorescent labeling capacity for biological systems.Keywords: core−shell nanoparticles; mesoporous silica; multifluorescence; transport carrier

Macroporous microspheres of SAPO-34 (MAMISAPO-34) were fabricated using polystyrene spheres (PS, 2 μm) as hard template. Cubic SAPO-34 (1 μm) synthesized by the conventional hydrothermal method was mixed with kaolin, silica sol, aluminium phosphate sol, template, and deionized water. Spray drying was then performed to prepare 30–50 μm microspheres which were converted to macroporous SAPO-34 by post-hydrothermal and calcination treatments. For comparison, 30–50 μm non-macroporous microspheres (NOMISAPO-34) were also obtained without using PS. XRD, NH3-TPD, and SEM analyses were used to characterize the macroporous and non-macroporous SAPO-34. The results showed that MAMISAPO-34 was more crystalline and had more strong acid sites than NOMISAPO-34. When used in MTO (methanol to olefins) reactions, MAMISAPO-34 had better catalytic performance than NOMISAPO-34, because of its greater crystallinity.

Incorporation of a dual-FRET dye pair into mesoporous silica nanoparticles yields sensitive and sensing-range tunable nanosensors with good reversibility that can be used for ratiometric pH measurements under a single-wavelength excitation.

Bi2WO6 nanoparticles loaded on a spherical MCM-48 mesoporous molecular sieve with a high photocatalytic activity in the visible-light range was synthesized for the first time using a facile one-step process.

Mesoporous ZSM-5 was synthesized by using dual templates and one step hydrothermal crystallization method under alkali conditions. Mesopores were created by using cetyltrimethylammonium bromide (CTAB) as the template and the crystallized pore wall framework was formed by using tetrapropylammonium bromide (TPAB) as the template. The specific influences of the polyethylene glycol (PEG) and ammonium fluoride (NH4F) addition, hydrothermal crystallization temperature, TPAB/Si and Al/Si ratio to the mesostructure and crystallinity of the obtained samples were carefully studied. In this system, PEG plays an important role in the maintenance of the mesoporous pore ordering and the zeolite crystallinity. Moreover, the study on the hydrothermal stability of the sample with best mesoporous pore ordering and zeolite crystallinity showed this kind mesoporous zeolite has extremely high hydrothermal stability in boiling water.

Highly sensitive surface-enhanced Raman scattering (SERS) detection was achieved on plasmon-free TiO2 photonic artificial microarray, which can be quickly recovered under simulated solar light irradiation and repeatedly used. The sensitive detection performance is attributed to the enhanced matter-light interaction through repeated and multiple light scattering in photonic microarray. Moreover, the SERS sensitivity is unprecedentedly found to be dependent on the different light-coupling performance of microarray with various photonic band gaps, where microarray with band gap center near to laser wavelength shows a lower SERS signal due to depressed light propagation, while those with band gap edges near to laser wavelength show higher sensitivity due to slow light effect.

Bi2WO6 nanoparticles loaded on a spherical MCM-48 mesoporous molecular sieve with a high photocatalytic activity in the visible-light range was synthesized for the first time using a facile one-step process.

Incorporation of a dual-FRET dye pair into mesoporous silica nanoparticles yields sensitive and sensing-range tunable nanosensors with good reversibility that can be used for ratiometric pH measurements under a single-wavelength excitation.

The Stöber process is revisited using vinyltriethoxysilane as the precursor, where a kinetics-controlled condensation of vinylsilanols, free from external fluorogens, unprecedentedly produces hydrophilic diamond-structured organosilica nanocrystals (ca. 2–6 nm) with finely tunable fluorescence (460–625 nm). The key to the synthesis lies in a slow successful condensation of vinylsilanols triggered and guided by the π–π stacking interaction of vinyl groups.

Plasmonic MoO3−x@MoO3 nanosheets obtained from surface oxidation of MoO3−x were employed as a SERS substrate for methylene blue detection. They exhibit extraordinary sensitivity comparable to noble metals, which is attributed to shell-isolated electromagnetic enhancing by the plasmonic MoO3−x core and elimination of the photocatalytic degradation by the MoO3 shell.