Bismuth-doped antimony tungstate(Bi-doped Sb_(2)WO_(6))microspheres were synthesized via a novel hydrothermal synthesis approach.These microspheres were then used as active layers in gas sensors for the detection of c...Bismuth-doped antimony tungstate(Bi-doped Sb_(2)WO_(6))microspheres were synthesized via a novel hydrothermal synthesis approach.These microspheres were then used as active layers in gas sensors for the detection of carbon dioxide(CO_(2)),a significant greenhouse gas and a critical parameter for evaluating air quality.The incorporation of bismuth significantly enhances the gas-sensing performance of the Sb_(2)WO_(6)microspheres,with the 4%Bidoped sensing active layer achieving a remarkable response value of 15 when exposed to 200 ppm of CO_(2),outperforming the undoped Sb_(2)WO_(6).Furthermore,the selectivity of the 4%Bi-Sb_(2)WO_(6)sensor toward CO_(2)gas was enhanced relative to the Sb_(2)WO_(6)sensor.The fundamental mechanisms of gas sensing and the factors contributing to the improved CO_(2)response of 4%Bi-Sb_(2)WO_(6)micro spheres were investigated using density functional theory.Bi-doped Sb_(2)WO_(6)materials exhibit significant advantages in gas-sensing applications,including improved conductivity,enhanced gas adsorption capacity,increased reaction rates,good chemical stability,excellent selectivity,and the ability to adjust electron density.These characteristics enable Bi-doped Sb_(2)WO_(6)to demonstrate higher sensitivity and rapid response capabilities in gas sensors,making it suitable for practical applications.展开更多
Catalytic hydrogenation of CO_(2)to ethanol is a promising solution to address the greenhouse gas(GHG)emissions,but many current catalysts face efficiency and cost challenges.Cobalt based catalysts are frequently exam...Catalytic hydrogenation of CO_(2)to ethanol is a promising solution to address the greenhouse gas(GHG)emissions,but many current catalysts face efficiency and cost challenges.Cobalt based catalysts are frequently examined due to their abundance,cost-efficiency,and effectiveness in the reaction,where managing the Co^(0)to Co^(δ+)ratio is essential.In this study,we adjusted support nature(Al_(2)O_(3),MgO-MgAl_(2)O_(4),and MgO)and reduction conditions to optimize this balance of Co^(0)to Co^(δ+)sites on the catalyst surface,enhancing ethanol production.The selectivity of ethanol reached 17.9%in a continuous flow fixed bed micro-reactor over 20 mol%Co@MgO-MgAl_(2)O_(4)(CoMgAl)catalyst at 270°C and 3.0 MPa,when reduced at 400°C for 8 h.Characterisation results coupled with activity analysis confirmed that mild reduction condition(400°C,10%H_(2)balance N_(2),8 h)with intermediate metal support interaction favoured the generation of partially reduced Co sites(Co^(δ+)and Co^(0)sites in single atom)over MgO-MgAl_(2)O_(4)surface,which promoted ethanol synthesis by coupling of dissociative(CHx^(∗))/non-dissociative(CHxO^(∗))intermediates,as confirmed by density functional theory analysis.Additionally,the CoMgAl,affordably prepared through the coprecipitation method,offers a potential alternative for CO_(2)hydrogenation to yield valuable chemicals.展开更多
Solid-waste-based activated carbon(AC)was utilized as a carbon source to synthesize a series of carbon-based functional material RAC-X(X=P and S,where P and S denote phosphoric and sulfuric acids,respectively).The tol...Solid-waste-based activated carbon(AC)was utilized as a carbon source to synthesize a series of carbon-based functional material RAC-X(X=P and S,where P and S denote phosphoric and sulfuric acids,respectively).The toluene adsorption capacities of the regeneration AC(RAC)samples can be significantly improved by adopting the heteroatomic modification strategy.RAC-P and RAC-S have the same specific surface area(1156 m^(2)/g)and similar porous structures.However,they have different toluene adsorption capacities,with 316.22 mg/g for RAC-P and 460.12 mg/g for RAC-S,which are 1.6 and 2.4 times greater than that for RAC.The X-ray photoelectron spectroscopy measurements showed that the increase in the amount ofπ–π^(2)chemical bond over the AC surface results in the improvement of the toluene adsorption performance.The density functional theory results showed that the S-containing functional groups loaded near the defect sites of RAC-S promote toluene adsorption.Moreover,reusability tests showed that RAC-S still retains 86%of its adsorption activity after four consecutive adsorption–desorption experiments.This indicates that the heteroatomic modification method affords excellent toluene adsorption performance and recycling practicability,which not only is beneficial for achieving the rational utilization of solid waste resources but also provides a practical method for the efficient elimination of volatile organic compounds.展开更多
基金financially supported by the Outstanding Youth Foundation of Jiangsu Province of China(No.BK20211548)Yangzhou Science and Technology Plan Project(No.YZ2023246)+1 种基金China Scholarship Council(No.202308320445)the Postgraduate Research and Practice Innovation Program of Jiangsu Province of China(No.KYCX23_3551)
文摘Bismuth-doped antimony tungstate(Bi-doped Sb_(2)WO_(6))microspheres were synthesized via a novel hydrothermal synthesis approach.These microspheres were then used as active layers in gas sensors for the detection of carbon dioxide(CO_(2)),a significant greenhouse gas and a critical parameter for evaluating air quality.The incorporation of bismuth significantly enhances the gas-sensing performance of the Sb_(2)WO_(6)microspheres,with the 4%Bidoped sensing active layer achieving a remarkable response value of 15 when exposed to 200 ppm of CO_(2),outperforming the undoped Sb_(2)WO_(6).Furthermore,the selectivity of the 4%Bi-Sb_(2)WO_(6)sensor toward CO_(2)gas was enhanced relative to the Sb_(2)WO_(6)sensor.The fundamental mechanisms of gas sensing and the factors contributing to the improved CO_(2)response of 4%Bi-Sb_(2)WO_(6)micro spheres were investigated using density functional theory.Bi-doped Sb_(2)WO_(6)materials exhibit significant advantages in gas-sensing applications,including improved conductivity,enhanced gas adsorption capacity,increased reaction rates,good chemical stability,excellent selectivity,and the ability to adjust electron density.These characteristics enable Bi-doped Sb_(2)WO_(6)to demonstrate higher sensitivity and rapid response capabilities in gas sensors,making it suitable for practical applications.
文摘Catalytic hydrogenation of CO_(2)to ethanol is a promising solution to address the greenhouse gas(GHG)emissions,but many current catalysts face efficiency and cost challenges.Cobalt based catalysts are frequently examined due to their abundance,cost-efficiency,and effectiveness in the reaction,where managing the Co^(0)to Co^(δ+)ratio is essential.In this study,we adjusted support nature(Al_(2)O_(3),MgO-MgAl_(2)O_(4),and MgO)and reduction conditions to optimize this balance of Co^(0)to Co^(δ+)sites on the catalyst surface,enhancing ethanol production.The selectivity of ethanol reached 17.9%in a continuous flow fixed bed micro-reactor over 20 mol%Co@MgO-MgAl_(2)O_(4)(CoMgAl)catalyst at 270°C and 3.0 MPa,when reduced at 400°C for 8 h.Characterisation results coupled with activity analysis confirmed that mild reduction condition(400°C,10%H_(2)balance N_(2),8 h)with intermediate metal support interaction favoured the generation of partially reduced Co sites(Co^(δ+)and Co^(0)sites in single atom)over MgO-MgAl_(2)O_(4)surface,which promoted ethanol synthesis by coupling of dissociative(CHx^(∗))/non-dissociative(CHxO^(∗))intermediates,as confirmed by density functional theory analysis.Additionally,the CoMgAl,affordably prepared through the coprecipitation method,offers a potential alternative for CO_(2)hydrogenation to yield valuable chemicals.
基金National key R&D Program of China(No.2022YFC3701903)natural science foundation of Shanxi Province(No.202203021211178)National Natural Science Foundation of China(51901209)for financial support.
文摘Solid-waste-based activated carbon(AC)was utilized as a carbon source to synthesize a series of carbon-based functional material RAC-X(X=P and S,where P and S denote phosphoric and sulfuric acids,respectively).The toluene adsorption capacities of the regeneration AC(RAC)samples can be significantly improved by adopting the heteroatomic modification strategy.RAC-P and RAC-S have the same specific surface area(1156 m^(2)/g)and similar porous structures.However,they have different toluene adsorption capacities,with 316.22 mg/g for RAC-P and 460.12 mg/g for RAC-S,which are 1.6 and 2.4 times greater than that for RAC.The X-ray photoelectron spectroscopy measurements showed that the increase in the amount ofπ–π^(2)chemical bond over the AC surface results in the improvement of the toluene adsorption performance.The density functional theory results showed that the S-containing functional groups loaded near the defect sites of RAC-S promote toluene adsorption.Moreover,reusability tests showed that RAC-S still retains 86%of its adsorption activity after four consecutive adsorption–desorption experiments.This indicates that the heteroatomic modification method affords excellent toluene adsorption performance and recycling practicability,which not only is beneficial for achieving the rational utilization of solid waste resources but also provides a practical method for the efficient elimination of volatile organic compounds.
