CO impurity-induced catalyst deactivation has long been one of the biggest challenges in proton-exchange membrane fuel cells,with the poisoning phenomenon mainly attributed to the overly strong adsorption on the catal...CO impurity-induced catalyst deactivation has long been one of the biggest challenges in proton-exchange membrane fuel cells,with the poisoning phenomenon mainly attributed to the overly strong adsorption on the catalytic site.Here,we present a mechanistic study that overturns this understanding by using Rh-based single-atom catalysis centers as model catalysts.We precisely modulated the chelation structure of the Rh catalyst by coordinating Rh with C or N atoms,and probed the reaction mechanism by surface-enhanced Raman spectroscopy.Direct spectroscopic evidence for intermediates indicates that the reactivity of adsorbed OH^(*),rather than the adsorption strength of CO^(*),dictates the CO electrocatalytic oxidation behavior.The RhN_(4)sites,which adsorb the OH^(*)intermediate more weakly than RhC4 sites,showed prominent CO oxidation activity that not only far exceeded the traditional Pt/C but also the RhC4 sites with similar CO adsorption strength.From this study,it is clear that a paradigm shift in future research should be considered to rationally design high-performance CO electro-oxidation reaction catalysts by sufficiently considering the water-related reaction intermediate during catalysis.展开更多
Silk fibroin(SF)can be used to construct various stiff material interfaces to support bone formation.An essential preparatory step is to partially transform SF molecules from random coils toβ-sheets to render the mat...Silk fibroin(SF)can be used to construct various stiff material interfaces to support bone formation.An essential preparatory step is to partially transform SF molecules from random coils toβ-sheets to render the material water insoluble.However,the influence of the SF conformation on osteogenic cell behavior at the material interface remains unknown.Herein,three stiff SF substrates were prepared by varying theβ-sheet content(high,medium,and low).The substrates had a comparable chemical composition,surface topography,and wettability.When adsorbed fibronectin was used as a model cellular adhesive protein,the stability of the adsorbed protein-material interface,in terms of the surface stability of the SF substrates and the accompanying fibronectin detachment resistance,increased with the increasingβ-sheet content of the SF substrates.Furthermore,(i)larger areas of cytoskeleton-associated focal adhesions,(ii)higher orders of cytoskeletal organization and(iii)more elongated cell spreading were observed for bone marrow-derived mesenchymal stromal cells(BMSCs)cultured on SF substrates with high vs.lowβ-sheet contents,along with enhanced nuclear translocation and activation of YAP/TAZ and RUNX2.Consequently,osteogenic differentiation of BMSCs was stimulated on highβ-sheet substrates.These results indicated that theβ-sheet content influences osteogenic differentiation of BMSCs on SF materials in vitro by modulating the stability of the adsorbed protein-material interface,which proceeds via protein-focal adhesion-cytoskeleton links and subsequent intracellular mechanotransduction.Our findings emphasize the role of the stability of the adsorbed protein-material interface in cellular mechanotransduction and the perception of stiff SF substrates with differentβ-sheet contents,which should not be overlooked when engineering stiff biomaterials.展开更多
I.r.bands at 1559.0, 1441 .0, 1378 .9, 13603, 1031. 1,981 .4 and 947.3 cm -1 due tovarious types of dissociative adsorption of H2 over ZrO2 with changing temperatore wereobserved by in situ FT-IR spectroscopy.
Surface enhanced Raman scattering of water adsorbed at silver electrodes in very negative potential region was first observed and a simple model related to the adsorption configuration is proposed.
It was observed that the p-aminobenzoic acid(PABA)molecules adsorbed on A92CO3 colloids exhibited strong SERS effect,the enhancement factor is estimated at 10~7—10~8 The mechanism of SERS effect on PABA adsorbed on t...It was observed that the p-aminobenzoic acid(PABA)molecules adsorbed on A92CO3 colloids exhibited strong SERS effect,the enhancement factor is estimated at 10~7—10~8 The mechanism of SERS effect on PABA adsorbed on the colloids was discussed.展开更多
Based on the nanostructured surface model that the (platinum, Pt) nanocones grow out symmetrically from a plane substrate, the local electric field near the conical nanoparticle surface is computed and discussed. On...Based on the nanostructured surface model that the (platinum, Pt) nanocones grow out symmetrically from a plane substrate, the local electric field near the conical nanoparticle surface is computed and discussed. On the basis of these results, the adsorbed CO molecules are modelled as dipoles, and three kinds of interactions, i.e. interactions between dipoles and local electric field, between dipoles and dipoles, as well as between dipoles and nanostructured substrate, are taken into account. The spatial configuration of CO molecules adsorbed on the nanocone surface is then given by Monte-Carlo simulation. Our results show that the CO molecules adsorbed on the nanocone surface cause local agglomeration under the action of an external electric field, and this agglomeration becomes more compact with decreasing conical angle, which results in a stronger interaction among molecules. These results serve as a basis for explaining abnormal phenomena such as the abnormal infrared effect (AIRE), which was found when CO molecules were adsorbed on the nanostructured transition-metal surface.展开更多
The paper presents ac impedance behaviours of phenyl iso-thiocyanate adsorbed on Pt electrode.Nyquist plots are analysed and simulated,and parameters of relative equivalent circuits are obtained.
A new reagent. trimethylammonium chlorochromate adsorbed on alumina, suitable for the oxidation of hydroxy compounds to the corresponding carbonyl compounds is described.
This paper shows that the local electric field distribution near the nanostructure metallic surface is obtained by solving the Laplace equation, and furthermore, the configuration of CO molecules adsorbed on a Pt nano...This paper shows that the local electric field distribution near the nanostructure metallic surface is obtained by solving the Laplace equation, and furthermore, the configuration of CO molecules adsorbed on a Pt nanoparticle surface is obtained by using Monte Carlo simulation. It is found that the uneven local electric field distribution induced by the nanostructure surface can influence the configuration of carbon monoxide (CO) molecules by a force, which drags the adsorbates to the poles of the nanoparticles. This result, together with our results obtained before, may explain the experimental results that the nanostructure metallic surface can lead to abnormal phenomena such as anti-absorption infrared effects.展开更多
SERRS has been developed for observing a weak enhancement of SERS.A SERS from dye molecules 1555 adsorbed on Copper surface was observed at 4880Åexcitation and this result could be qualitatively explained by the ...SERRS has been developed for observing a weak enhancement of SERS.A SERS from dye molecules 1555 adsorbed on Copper surface was observed at 4880Åexcitation and this result could be qualitatively explained by the antenna model of SERS.展开更多
The orientational ordering in adsorbed incommensurate monolayers is discussed in an anharmonic approach.A nonlinear relationship is predicted between the orientation of the monolayer relative to the substrate and the ...The orientational ordering in adsorbed incommensurate monolayers is discussed in an anharmonic approach.A nonlinear relationship is predicted between the orientation of the monolayer relative to the substrate and the monolayer lattice parameter.Calculated values of the rninimum energy crientation angle for Ar on graphite are in good agreement with the experimental reported measurements.展开更多
The SERS spectrum of C_(60) was obtained by using silver mirror. From the SERS spectrum of C_(60) and the IR spectrum of C_(60), we proposed that C_(60) adsorbed on the silver mirror adopts a more ellipsoidal shape.
Activated carbon (AC) supported silver catalysts were prepared by incipient wetness impregnation method and their catalytic performance for CO preferential oxidation (PROX) in excess H2 was evaluated. Ag/AC cataly...Activated carbon (AC) supported silver catalysts were prepared by incipient wetness impregnation method and their catalytic performance for CO preferential oxidation (PROX) in excess H2 was evaluated. Ag/AC catalysts, after reduction in H2 at low temperatures (≤200 ℃) following heat treatment in He at 200 ℃ (He200H200), exhibited the best catalytic properties. Temperature-programmed desorption (TPD), X-ray diffraction (XRD) and temperature-programmed reduction (TPR) results indicated that silver oxides were produced during heat treatment in He at 200 ℃ which were reduced to metal silver nanoparticles in H2 at low temperatures (≤200 ℃), simultaneously generating the adsorbed water/OH. CO conversion was enhanced 40% after water treatment following heat treatment in He at 600 ℃. These results imply that the metal silver nanoparticles are the active species and the adsorbed water/OH has noticeable promotion effects on CO oxidation. However, the promotion effect is still limited compared to gold catalysts under the similar conditions, which may be the reason of low selectivity to CO oxidation in PROX over silver catalysts. The reported Ag/AC-S-He catalyst after He200H200 treatment displayed similar PROX of CO reaction properties to Ag/SiO2. This means that Ag/AC catalyst is also an efficient low-temperature CO oxidation catalyst.展开更多
The binding energies of ethylene oxide (Et-O) adsorbed on Cu(110) surface for different adsorption sites and orientations are calculated with an atom superposition and electron delocalization molecular orbital (ASED-M...The binding energies of ethylene oxide (Et-O) adsorbed on Cu(110) surface for different adsorption sites and orientations are calculated with an atom superposition and electron delocalization molecular orbital (ASED-MO) using cluster models. It shows that the top site of Cu(110) surface is preferable for Et-O adsorption and the orientation of C-C bond of Et-O is parallel to the [110] direction of the substratc. The distance of an oxygen of Et-O to the Cu atom is approximately 1.5817(?). It is different from the supposition of C. Benndorf et al., in which the oxygen was proposed on the short bridge site with C-C bond orientating to [110] direction of Cu(110)展开更多
The behavior of chloride adsorbed on Ag(100) electrode has been studied using chronoamperometric technique, and the structural transition of chloride layer has been confirmed.
The SiO 2 adsorbing YF 3, Y 2(CO 3) 3, Y 2(C 2O 4) 3 and YPO 4, respectively, formed four systems of particle materials: SiO 2·YF 3, SiO 2·Y 2(CO 3) 3 , SiO 2·Y 2(C 2O 4) 3 and SiO ...The SiO 2 adsorbing YF 3, Y 2(CO 3) 3, Y 2(C 2O 4) 3 and YPO 4, respectively, formed four systems of particle materials: SiO 2·YF 3, SiO 2·Y 2(CO 3) 3 , SiO 2·Y 2(C 2O 4) 3 and SiO 2·YPO 4. The electrorheological(ER) behavior of the electrorheological fluids (ERF) prepared by dispersing them in silicone oil was tested at 20 ℃ under d.c. field. The results show that the system of SiO 2·YF 3 does not display ER activity, and the ER performance of the particle materials of SiO 2·Y 2(CO 3) 3 is the best among them. The shearing stress of ERF with SiO 2·Y 2(CO 3) 3 particles is 1.644 KPa and the relative viscosity η r(=η E/η 0) is 20.3 (under field strength E=4200 V·mm -1) while the adsorbed content of Y 2(CO 3) 3 in the SiO 2 particle materials is 12.4%(mass fraction).展开更多
Heterogeneous photocatalysts exhibit high catalytic efficiency in the degradation of pollutants,but their stability and repeatability is not very good and requires high structural matching.Simply by nanosizing the pur...Heterogeneous photocatalysts exhibit high catalytic efficiency in the degradation of pollutants,but their stability and repeatability is not very good and requires high structural matching.Simply by nanosizing the pure Bi_(2)WO_(6)(BWO)photocatalyst without constructing a heterojunction,there is a significant improvement in its performance,with an enhancement effect of about 2.3 times(99.43%).The high photocatalytic degradation efficiency of the material can be attributed to the enhanced light absorption effect brought by the three-dimensional inverse-opal structure SiO_(2)(IS)and the abundant surface adsorbed oxygen generated after the formation of Si–O–W bonds.In addition,the introduction of IS greatly increases the surface area of nanostructured BWO,which accelerates the charge transfer process,while the adsorbed oxygen promotes the participation of·O^(2−) in the photocatalytic reaction,thereby accelerating the consumption of photo-generated electrons and ultimately improving the separation of charge carriers.Furthermore,the matched photonic bandgap further improves the absorption and utilization of light of the material.In this work,we constructs Si–O–W bonds to obtain inverse-opal SiO_(2)/Bi_(2)WO_(6) with uniformly growth of pure phase nano BWO,which provides a feasible strategy for the preparation of high-performance pure-phase photocatalysts.展开更多
Exploiting efficient and low-cost cocatalyst with a facile grafting strategy is of critical importance for significantly boosting the photocatalytic H2-evolution activity.In this study,S2^--adsorbed MoSx nanoparticle ...Exploiting efficient and low-cost cocatalyst with a facile grafting strategy is of critical importance for significantly boosting the photocatalytic H2-evolution activity.In this study,S2^--adsorbed MoSx nanoparticle as a superior H2-evolutoin cocatalyst was successfully grafted on the TiO2 surface to greatly boost its photocatalytic activity via one-step lactic acid-induced synthesis strategy.Herein,the lactic acid can induce the homogeneous production of amorphous MoSx(a-MoSx)nanoparticles from MoS42-precursor,while the symbiotic S2^-ions can be easily and availably self-adsorbed on the a-Mo Sxsurface,resulting in the formation of S2^--adsorbed a-Mo Sxnanoparticles with a small size of 0.5-3 nm.Photocatalytic results manifested that the S2^--adsorbed Mo Sxnanoparticles could dramatically facilitate the H2-generation rate of TiO2 photocatalysts(3452μmol h^-1 g^-1,AQE=16.5%).In situ irradiated XPS in conjunction with transient-state PL and photoelectrochemical tests reveal that the improved H_(2)-generation activity can be ascribed to the synergistic effect of boosted interfacial charge transfer from TiO_(2) to S^(2-)adsorbed Mo Sx and the superior H_(2)-evolution reaction on self-adsorbed S_(2-)ions.In addition,the S^(2-)-adsorbed Mo Sx nanoparticles can also act as the general H_(2)-generation cocatalyst to obviously promote the activity of other typical host photocatalysts such as g-C_(3) N_(4) and Cd S.This work provides an innovative approach to develop high-efficiency Mo Sx-based cocatalyst with boosted interfacial charge transfer toward highly efficient photocatalytic materials.展开更多
基金Jilin Province Science and Technology Development Program,Grant/Award Numbers:20180101030JC,20190201270JC,20200201001JCNational Natural Science Foundation of China,Grant/Award Numbers:21633008,21673221,21875243,U1601211+1 种基金Research Innovation Fund,Grant/Award Number:DNL202010Special Funds for Guiding Local Scientific and Technological Development by the Central Government,Grant/Award Number:2020JH6/10500021。
文摘CO impurity-induced catalyst deactivation has long been one of the biggest challenges in proton-exchange membrane fuel cells,with the poisoning phenomenon mainly attributed to the overly strong adsorption on the catalytic site.Here,we present a mechanistic study that overturns this understanding by using Rh-based single-atom catalysis centers as model catalysts.We precisely modulated the chelation structure of the Rh catalyst by coordinating Rh with C or N atoms,and probed the reaction mechanism by surface-enhanced Raman spectroscopy.Direct spectroscopic evidence for intermediates indicates that the reactivity of adsorbed OH^(*),rather than the adsorption strength of CO^(*),dictates the CO electrocatalytic oxidation behavior.The RhN_(4)sites,which adsorb the OH^(*)intermediate more weakly than RhC4 sites,showed prominent CO oxidation activity that not only far exceeded the traditional Pt/C but also the RhC4 sites with similar CO adsorption strength.From this study,it is clear that a paradigm shift in future research should be considered to rationally design high-performance CO electro-oxidation reaction catalysts by sufficiently considering the water-related reaction intermediate during catalysis.
基金supported by the National Key R&D Program of China(2017YFC1104301,to L.C.)the National Natural Science Foundation of China for Distinguished Young Scholars(31725011,to L.C.)the China Scholarship Council(201606160095,to X.C.)。
文摘Silk fibroin(SF)can be used to construct various stiff material interfaces to support bone formation.An essential preparatory step is to partially transform SF molecules from random coils toβ-sheets to render the material water insoluble.However,the influence of the SF conformation on osteogenic cell behavior at the material interface remains unknown.Herein,three stiff SF substrates were prepared by varying theβ-sheet content(high,medium,and low).The substrates had a comparable chemical composition,surface topography,and wettability.When adsorbed fibronectin was used as a model cellular adhesive protein,the stability of the adsorbed protein-material interface,in terms of the surface stability of the SF substrates and the accompanying fibronectin detachment resistance,increased with the increasingβ-sheet content of the SF substrates.Furthermore,(i)larger areas of cytoskeleton-associated focal adhesions,(ii)higher orders of cytoskeletal organization and(iii)more elongated cell spreading were observed for bone marrow-derived mesenchymal stromal cells(BMSCs)cultured on SF substrates with high vs.lowβ-sheet contents,along with enhanced nuclear translocation and activation of YAP/TAZ and RUNX2.Consequently,osteogenic differentiation of BMSCs was stimulated on highβ-sheet substrates.These results indicated that theβ-sheet content influences osteogenic differentiation of BMSCs on SF materials in vitro by modulating the stability of the adsorbed protein-material interface,which proceeds via protein-focal adhesion-cytoskeleton links and subsequent intracellular mechanotransduction.Our findings emphasize the role of the stability of the adsorbed protein-material interface in cellular mechanotransduction and the perception of stiff SF substrates with differentβ-sheet contents,which should not be overlooked when engineering stiff biomaterials.
文摘I.r.bands at 1559.0, 1441 .0, 1378 .9, 13603, 1031. 1,981 .4 and 947.3 cm -1 due tovarious types of dissociative adsorption of H2 over ZrO2 with changing temperatore wereobserved by in situ FT-IR spectroscopy.
文摘Surface enhanced Raman scattering of water adsorbed at silver electrodes in very negative potential region was first observed and a simple model related to the adsorption configuration is proposed.
文摘It was observed that the p-aminobenzoic acid(PABA)molecules adsorbed on A92CO3 colloids exhibited strong SERS effect,the enhancement factor is estimated at 10~7—10~8 The mechanism of SERS effect on PABA adsorbed on the colloids was discussed.
基金supported by the Natural Science Foundation of Fujian Province of China (Grant Nos C0710036 and T0750008)
文摘Based on the nanostructured surface model that the (platinum, Pt) nanocones grow out symmetrically from a plane substrate, the local electric field near the conical nanoparticle surface is computed and discussed. On the basis of these results, the adsorbed CO molecules are modelled as dipoles, and three kinds of interactions, i.e. interactions between dipoles and local electric field, between dipoles and dipoles, as well as between dipoles and nanostructured substrate, are taken into account. The spatial configuration of CO molecules adsorbed on the nanocone surface is then given by Monte-Carlo simulation. Our results show that the CO molecules adsorbed on the nanocone surface cause local agglomeration under the action of an external electric field, and this agglomeration becomes more compact with decreasing conical angle, which results in a stronger interaction among molecules. These results serve as a basis for explaining abnormal phenomena such as the abnormal infrared effect (AIRE), which was found when CO molecules were adsorbed on the nanostructured transition-metal surface.
文摘The paper presents ac impedance behaviours of phenyl iso-thiocyanate adsorbed on Pt electrode.Nyquist plots are analysed and simulated,and parameters of relative equivalent circuits are obtained.
文摘A new reagent. trimethylammonium chlorochromate adsorbed on alumina, suitable for the oxidation of hydroxy compounds to the corresponding carbonyl compounds is described.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10225420, 90206039 and 20021002).
文摘This paper shows that the local electric field distribution near the nanostructure metallic surface is obtained by solving the Laplace equation, and furthermore, the configuration of CO molecules adsorbed on a Pt nanoparticle surface is obtained by using Monte Carlo simulation. It is found that the uneven local electric field distribution induced by the nanostructure surface can influence the configuration of carbon monoxide (CO) molecules by a force, which drags the adsorbates to the poles of the nanoparticles. This result, together with our results obtained before, may explain the experimental results that the nanostructure metallic surface can lead to abnormal phenomena such as anti-absorption infrared effects.
基金supported by the Science Fund of the Chinese-Academy of Sciences。
文摘SERRS has been developed for observing a weak enhancement of SERS.A SERS from dye molecules 1555 adsorbed on Copper surface was observed at 4880Åexcitation and this result could be qualitatively explained by the antenna model of SERS.
基金the Science Fund of the Chinese Academy of Sciences。
文摘The orientational ordering in adsorbed incommensurate monolayers is discussed in an anharmonic approach.A nonlinear relationship is predicted between the orientation of the monolayer relative to the substrate and the monolayer lattice parameter.Calculated values of the rninimum energy crientation angle for Ar on graphite are in good agreement with the experimental reported measurements.
文摘The SERS spectrum of C_(60) was obtained by using silver mirror. From the SERS spectrum of C_(60) and the IR spectrum of C_(60), we proposed that C_(60) adsorbed on the silver mirror adopts a more ellipsoidal shape.
基金supported by the National Natural Science Foundation of China (No. 21207039)the Natural Science Foundation of Guangdong Province, China (Grant No. S2011010000737)+2 种基金the Doctoral Fund of Ministry of Education of China (20110172120017)the Fundamental Research Funds for the Central Universities (Grant No. 2011zm 0048)the Key Laboratory of Renewable Energy and Gas Hydrate, Chinese Academy of Sciences (No. Y007K1)
文摘Activated carbon (AC) supported silver catalysts were prepared by incipient wetness impregnation method and their catalytic performance for CO preferential oxidation (PROX) in excess H2 was evaluated. Ag/AC catalysts, after reduction in H2 at low temperatures (≤200 ℃) following heat treatment in He at 200 ℃ (He200H200), exhibited the best catalytic properties. Temperature-programmed desorption (TPD), X-ray diffraction (XRD) and temperature-programmed reduction (TPR) results indicated that silver oxides were produced during heat treatment in He at 200 ℃ which were reduced to metal silver nanoparticles in H2 at low temperatures (≤200 ℃), simultaneously generating the adsorbed water/OH. CO conversion was enhanced 40% after water treatment following heat treatment in He at 600 ℃. These results imply that the metal silver nanoparticles are the active species and the adsorbed water/OH has noticeable promotion effects on CO oxidation. However, the promotion effect is still limited compared to gold catalysts under the similar conditions, which may be the reason of low selectivity to CO oxidation in PROX over silver catalysts. The reported Ag/AC-S-He catalyst after He200H200 treatment displayed similar PROX of CO reaction properties to Ag/SiO2. This means that Ag/AC catalyst is also an efficient low-temperature CO oxidation catalyst.
文摘The binding energies of ethylene oxide (Et-O) adsorbed on Cu(110) surface for different adsorption sites and orientations are calculated with an atom superposition and electron delocalization molecular orbital (ASED-MO) using cluster models. It shows that the top site of Cu(110) surface is preferable for Et-O adsorption and the orientation of C-C bond of Et-O is parallel to the [110] direction of the substratc. The distance of an oxygen of Et-O to the Cu atom is approximately 1.5817(?). It is different from the supposition of C. Benndorf et al., in which the oxygen was proposed on the short bridge site with C-C bond orientating to [110] direction of Cu(110)
文摘The behavior of chloride adsorbed on Ag(100) electrode has been studied using chronoamperometric technique, and the structural transition of chloride layer has been confirmed.
文摘The SiO 2 adsorbing YF 3, Y 2(CO 3) 3, Y 2(C 2O 4) 3 and YPO 4, respectively, formed four systems of particle materials: SiO 2·YF 3, SiO 2·Y 2(CO 3) 3 , SiO 2·Y 2(C 2O 4) 3 and SiO 2·YPO 4. The electrorheological(ER) behavior of the electrorheological fluids (ERF) prepared by dispersing them in silicone oil was tested at 20 ℃ under d.c. field. The results show that the system of SiO 2·YF 3 does not display ER activity, and the ER performance of the particle materials of SiO 2·Y 2(CO 3) 3 is the best among them. The shearing stress of ERF with SiO 2·Y 2(CO 3) 3 particles is 1.644 KPa and the relative viscosity η r(=η E/η 0) is 20.3 (under field strength E=4200 V·mm -1) while the adsorbed content of Y 2(CO 3) 3 in the SiO 2 particle materials is 12.4%(mass fraction).
基金supported by the National Natural Science Foundation of China(grant No.52173214)the Youth Innovation Team of Shaanxi Universities(grant No.2022-70).
文摘Heterogeneous photocatalysts exhibit high catalytic efficiency in the degradation of pollutants,but their stability and repeatability is not very good and requires high structural matching.Simply by nanosizing the pure Bi_(2)WO_(6)(BWO)photocatalyst without constructing a heterojunction,there is a significant improvement in its performance,with an enhancement effect of about 2.3 times(99.43%).The high photocatalytic degradation efficiency of the material can be attributed to the enhanced light absorption effect brought by the three-dimensional inverse-opal structure SiO_(2)(IS)and the abundant surface adsorbed oxygen generated after the formation of Si–O–W bonds.In addition,the introduction of IS greatly increases the surface area of nanostructured BWO,which accelerates the charge transfer process,while the adsorbed oxygen promotes the participation of·O^(2−) in the photocatalytic reaction,thereby accelerating the consumption of photo-generated electrons and ultimately improving the separation of charge carriers.Furthermore,the matched photonic bandgap further improves the absorption and utilization of light of the material.In this work,we constructs Si–O–W bonds to obtain inverse-opal SiO_(2)/Bi_(2)WO_(6) with uniformly growth of pure phase nano BWO,which provides a feasible strategy for the preparation of high-performance pure-phase photocatalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.51872221 and 21771142)the Fundamental Research Funds for the Central Universities(No.WUT 2019IB002)。
文摘Exploiting efficient and low-cost cocatalyst with a facile grafting strategy is of critical importance for significantly boosting the photocatalytic H2-evolution activity.In this study,S2^--adsorbed MoSx nanoparticle as a superior H2-evolutoin cocatalyst was successfully grafted on the TiO2 surface to greatly boost its photocatalytic activity via one-step lactic acid-induced synthesis strategy.Herein,the lactic acid can induce the homogeneous production of amorphous MoSx(a-MoSx)nanoparticles from MoS42-precursor,while the symbiotic S2^-ions can be easily and availably self-adsorbed on the a-Mo Sxsurface,resulting in the formation of S2^--adsorbed a-Mo Sxnanoparticles with a small size of 0.5-3 nm.Photocatalytic results manifested that the S2^--adsorbed Mo Sxnanoparticles could dramatically facilitate the H2-generation rate of TiO2 photocatalysts(3452μmol h^-1 g^-1,AQE=16.5%).In situ irradiated XPS in conjunction with transient-state PL and photoelectrochemical tests reveal that the improved H_(2)-generation activity can be ascribed to the synergistic effect of boosted interfacial charge transfer from TiO_(2) to S^(2-)adsorbed Mo Sx and the superior H_(2)-evolution reaction on self-adsorbed S_(2-)ions.In addition,the S^(2-)-adsorbed Mo Sx nanoparticles can also act as the general H_(2)-generation cocatalyst to obviously promote the activity of other typical host photocatalysts such as g-C_(3) N_(4) and Cd S.This work provides an innovative approach to develop high-efficiency Mo Sx-based cocatalyst with boosted interfacial charge transfer toward highly efficient photocatalytic materials.