Photocatalytic overall pure water splitting is a promising method for generating green hydrogen energy under mild conditions.However,this process is often hindered by sluggish electron-hole separation and transport.To...Photocatalytic overall pure water splitting is a promising method for generating green hydrogen energy under mild conditions.However,this process is often hindered by sluggish electron-hole separation and transport.To address this,a step-scheme(S-scheme)B-doped N-deficient C_(3)N_(4)/O-doped C_(3)N_(5)(BN-C_(3)N_(4)/O-C_(3)N_(5))heterojunction with interfacial B-O bonds has been constructed.Utilizing Pt and Co(OH)_(2) as co-catalysts,BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction demonstrates significantly enhanced photocatalytic activity for overall pure water splitting under visible light,achieving H_(2) and O_(2) evolution rates of 40.12 and 19.62μmol/h,respectively.Systematic characterizations and experiments revealed the performance-enhancing effects of the enhanced built-in electric field and the interfacial B-O bonding.Firstly,the strengthened built-in electric field provides sufficient force for rapid interfacial electron transport.Secondly,by reducing the transport energy barrier and transfer distance,the interfacial B-O bonds facilitate rapid recombination of electrons and holes with relatively low redox potential via the S-scheme charge-transfer route,leaving the high-potential electrons and holes available for H^(+)reduction and OH^(-)oxidation reactions.Overall,the photocatalytic efficiency of BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction was significantly improved,making it a promising approach for green hydrogen production through overall pure water splitting.展开更多
For CO catalytic oxidation,Cu and Ce species are of great importance,between which the synergistic effect is worth investigating.In this work,CeO_(2)/Cu_(2)O with Cu_(2)O{111}and{100}planes were comparatively explored...For CO catalytic oxidation,Cu and Ce species are of great importance,between which the synergistic effect is worth investigating.In this work,CeO_(2)/Cu_(2)O with Cu_(2)O{111}and{100}planes were comparatively explored on CO catalytic oxidation to reveal the effects of interfacial electronic interactions and oxygen defects.The activity result demonstrates that CeO_(2)/o-Cu_(2)O{111}has superior performance compared with CeO_(2)/c-Cu_(2)O{100}.Credit to the coordination unsaturated copper atoms(Cu_(CUS))on oCu_(2)O{111}surface,the interfacial electronic interactions on CeO_(2)/o-Cu_(2)O{111}are more obvious than those on CeO_(2)/c-Cu_(2)O{100},leading to richer oxygen defect generation,better redox and activation abilities of CO and O_(2)reactants.Furthermore,the reaction mechanism of CeO_(2)/o-Cu_(2)O{111}on CO oxidation is revealed,i.e.,CO and O_(2)are adsorbed on the Cucus on Cu_(2)O{111}and oxygen defect of CeO_(2),respectively,and then synergistically promote the CO oxidation to CO_(2).The work sheds light on the designing optimized ceria and copper-based catalysts and the mechanism of CO oxidation.展开更多
Cerium‐based catalysts are very attractive for the catalytic abatement of nitrogen oxides(NOx)emitted from stationary sources.However,the main challenge is still achieving satisfactory catalytic activity in the low‐...Cerium‐based catalysts are very attractive for the catalytic abatement of nitrogen oxides(NOx)emitted from stationary sources.However,the main challenge is still achieving satisfactory catalytic activity in the low‐temperature range and tolerance to SO2 poisoning.In the present work,two series of Mo‐modified CeO_(2)catalysts were respectively obtained through a wet impregnation method(Mo‐CeO_(2))and a co‐precipitation method(MoCe‐cp),and the roles of the Mo species were systematically investigated.Activity tests showed that the Mo‐CeO_(2)catalyst displayed much higher NO conversion at low temperature and anti‐SO2 ability than MoCe‐cp.The optimal Mo‐CeO_(2)catalyst displayed over 80%NO elimination efficiency even at 150°C and remarkable SO2 resistance at 250°C(nearly no activity loss after 40 h test).The characterization results indicated that the introduced Mo species were highly dispersed on the Mo‐CeO_(2)catalyst surface,thereby providing more Brønsted acid sites and inhibiting the formation of stable adsorbed NOx species.These factors synergistically promote the selective catalytic reduction(SCR)reaction in accordance with the Eley‐Rideal(E‐R)reaction path on the Mo‐CeO_(2)catalyst.Additionally,the molybdenum surface could protect CeO_(2)from SO2 poisoning;thus,the reducibility of the Mo‐CeO_(2)catalyst declined slightly to an adequate level after sulfation.The results in this work indicate that surface modification with Mo species may be a simple method of developing highly efficient cerium‐based SCR catalysts with superior SO2 durability.展开更多
基金supported by the National Natural Science Foundation of China(No.62004143)the Key R&D Program of Hubei Province(No.2022BAA084)the Major Project of Natural Science Foundation of Jiangsu Universities,China(No.23KJA150010)。
文摘Photocatalytic overall pure water splitting is a promising method for generating green hydrogen energy under mild conditions.However,this process is often hindered by sluggish electron-hole separation and transport.To address this,a step-scheme(S-scheme)B-doped N-deficient C_(3)N_(4)/O-doped C_(3)N_(5)(BN-C_(3)N_(4)/O-C_(3)N_(5))heterojunction with interfacial B-O bonds has been constructed.Utilizing Pt and Co(OH)_(2) as co-catalysts,BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction demonstrates significantly enhanced photocatalytic activity for overall pure water splitting under visible light,achieving H_(2) and O_(2) evolution rates of 40.12 and 19.62μmol/h,respectively.Systematic characterizations and experiments revealed the performance-enhancing effects of the enhanced built-in electric field and the interfacial B-O bonding.Firstly,the strengthened built-in electric field provides sufficient force for rapid interfacial electron transport.Secondly,by reducing the transport energy barrier and transfer distance,the interfacial B-O bonds facilitate rapid recombination of electrons and holes with relatively low redox potential via the S-scheme charge-transfer route,leaving the high-potential electrons and holes available for H^(+)reduction and OH^(-)oxidation reactions.Overall,the photocatalytic efficiency of BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction was significantly improved,making it a promising approach for green hydrogen production through overall pure water splitting.
基金Project supported by the National Natural Science Foundation of China(21707066,21677069)。
文摘For CO catalytic oxidation,Cu and Ce species are of great importance,between which the synergistic effect is worth investigating.In this work,CeO_(2)/Cu_(2)O with Cu_(2)O{111}and{100}planes were comparatively explored on CO catalytic oxidation to reveal the effects of interfacial electronic interactions and oxygen defects.The activity result demonstrates that CeO_(2)/o-Cu_(2)O{111}has superior performance compared with CeO_(2)/c-Cu_(2)O{100}.Credit to the coordination unsaturated copper atoms(Cu_(CUS))on oCu_(2)O{111}surface,the interfacial electronic interactions on CeO_(2)/o-Cu_(2)O{111}are more obvious than those on CeO_(2)/c-Cu_(2)O{100},leading to richer oxygen defect generation,better redox and activation abilities of CO and O_(2)reactants.Furthermore,the reaction mechanism of CeO_(2)/o-Cu_(2)O{111}on CO oxidation is revealed,i.e.,CO and O_(2)are adsorbed on the Cucus on Cu_(2)O{111}and oxygen defect of CeO_(2),respectively,and then synergistically promote the CO oxidation to CO_(2).The work sheds light on the designing optimized ceria and copper-based catalysts and the mechanism of CO oxidation.
文摘Cerium‐based catalysts are very attractive for the catalytic abatement of nitrogen oxides(NOx)emitted from stationary sources.However,the main challenge is still achieving satisfactory catalytic activity in the low‐temperature range and tolerance to SO2 poisoning.In the present work,two series of Mo‐modified CeO_(2)catalysts were respectively obtained through a wet impregnation method(Mo‐CeO_(2))and a co‐precipitation method(MoCe‐cp),and the roles of the Mo species were systematically investigated.Activity tests showed that the Mo‐CeO_(2)catalyst displayed much higher NO conversion at low temperature and anti‐SO2 ability than MoCe‐cp.The optimal Mo‐CeO_(2)catalyst displayed over 80%NO elimination efficiency even at 150°C and remarkable SO2 resistance at 250°C(nearly no activity loss after 40 h test).The characterization results indicated that the introduced Mo species were highly dispersed on the Mo‐CeO_(2)catalyst surface,thereby providing more Brønsted acid sites and inhibiting the formation of stable adsorbed NOx species.These factors synergistically promote the selective catalytic reduction(SCR)reaction in accordance with the Eley‐Rideal(E‐R)reaction path on the Mo‐CeO_(2)catalyst.Additionally,the molybdenum surface could protect CeO_(2)from SO2 poisoning;thus,the reducibility of the Mo‐CeO_(2)catalyst declined slightly to an adequate level after sulfation.The results in this work indicate that surface modification with Mo species may be a simple method of developing highly efficient cerium‐based SCR catalysts with superior SO2 durability.
