Novel graphitic carbon nitride(g-C_(3)N_(4))nanosheet/Bi_(5)O_(7)Br/NH_(2)-MIL-88B(Fe)photocatalysts(denoted as GCN-NSh/Bi_(5)O_(7)Br/FeMOF,in which MOF is metal–organic framework)with double S-scheme heterojunctions...Novel graphitic carbon nitride(g-C_(3)N_(4))nanosheet/Bi_(5)O_(7)Br/NH_(2)-MIL-88B(Fe)photocatalysts(denoted as GCN-NSh/Bi_(5)O_(7)Br/FeMOF,in which MOF is metal–organic framework)with double S-scheme heterojunctions were synthesized by a facile solvothermal route.The resultant materials were examined by X-ray photoelectron spectrometer(XPS),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDX),transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),photoluminescence spectroscopy(PL),Fourier transform infrared spectroscopy(FT-IR),UV-Vis diffuse reflection spectroscopy(UV-vis DRS),photocurrent density,electrochemical impedance spectroscopy(EIS),and Brunauer–Emmett–Teller(BET)analyses.After the integration of Fe-MOF with GCN-NSh/Bi_(5)O_(7)Br,the removal constant of tetracycline over the optimal GCN-NSh/Bi_(5)O_(7)Br/Fe-MOF(15wt%)nanocomposite was promoted 33 times compared with that of the pristine GCN.The GCN-NSh/Bi_(5)O_(7)Br/Fe-MOF(15wt%)nanocomposite showed superior photoactivity to azithromycin,metronidazole,and cephalexin removal that was 36.4,20.2,and 14.6 times higher than that of pure GCN,respectively.Radical quenching tests showed that·O_(2)-and h+mainly contributed to the elimination reaction.In addition,the nanocomposite maintained excellent activity after 4 successive cycles.Based on the developed n–n heterojunctions among n-GCN-NSh,n-Bi_(5)O_(7)Br,and n-Fe-MOF semiconductors,the double S-scheme charge transfer mechanism was proposed for the destruction of the selected antibiotics.展开更多
采用超声辅助室温原位沉淀法合成BC/Bi_(4)O_(5)Br_(2)光催化剂,在可见光下对比了TiO_(2)体系、BC/Bi_(4)O_(5)Br_(2)体系以及BC/Bi_(4)O_(5)Br_(2)耦合过一硫酸盐(PMS)体系处理渗滤液尾水的效果。考察了BC/Bi_(4)O_(5)Br_(2)耦合PMS体...采用超声辅助室温原位沉淀法合成BC/Bi_(4)O_(5)Br_(2)光催化剂,在可见光下对比了TiO_(2)体系、BC/Bi_(4)O_(5)Br_(2)体系以及BC/Bi_(4)O_(5)Br_(2)耦合过一硫酸盐(PMS)体系处理渗滤液尾水的效果。考察了BC/Bi_(4)O_(5)Br_(2)耦合PMS体系中PMS投加量和反应时间的影响,通过紫外可见光谱、三维荧光图谱分析渗滤液尾水有机物成分。结果表明:BC/Bi_(4)O_(5)Br_(2)耦合PMS体系对腐殖质的去除效果较另外两体系的效果优异,BC/Bi_(4)O_(5)Br_(2)对COD、腐殖质(A_(254))、色度(CN)的去除率分别为13.07%、12.74%、52.19%,BOD_(5)/COD从0.08提升至0.18。BC/Bi_(4)O_(5)Br_(2)耦合PMS体系中,0.1 g BC/Bi_(4)O_(5)Br_(2)耦合0.20 g PMS体系对渗滤液尾水有机物有良好的降解效果,尤其在反应开始的前0.5 h作用效果明显,1.5 h后降解效率不再明显增加。BC/Bi_(4)O_(5)Br_(2)耦合PMS体系对TOC的最大去除率为30.5%,较BC/Bi_(4)O_(5)Br_(2)体系提高16.5%;对腐殖质的最大去除率为53.97%,较BC/Bi_(4)O_(5)Br_(2)体系提升41.5%。紫外可见光谱、三维荧光图谱表明渗滤液尾水以类腐殖质为主。研究结果可为非均相耦合过一硫酸盐光催化处理渗滤液尾水提供一定参考。展开更多
采用水热-煅烧法制备了磁性镍铁尖晶石载体NiFe_(2)O_(4),再采用浸渍-还原法在载体上负载Ru纳米粒子制备Ru/NiFe_(2)O_(4)催化剂。采用X射线衍射(XRD)、N2吸附-脱附(BET)、NH3程序升温脱附(NH3-TPD)、H_(2)程序升温还原(H_(2)-TPR)、X...采用水热-煅烧法制备了磁性镍铁尖晶石载体NiFe_(2)O_(4),再采用浸渍-还原法在载体上负载Ru纳米粒子制备Ru/NiFe_(2)O_(4)催化剂。采用X射线衍射(XRD)、N2吸附-脱附(BET)、NH3程序升温脱附(NH3-TPD)、H_(2)程序升温还原(H_(2)-TPR)、X射线光电子能谱(XPS)和电感耦合等离子体发射光谱(ICP-OES)测试对催化剂进行表征分析。结果表明,Ru/NiFe_(2)O_(4)催化剂表面氧物种丰富,相较于载体,负载Ru后催化剂比表面积和表面酸量增加,Ru与载体存在相互作用,这可能是催化剂高活性和高稳定性的关键。将催化剂用于5-羟甲基糠醛(HMF)的选择性氧化,负载Ru后,催化剂催化活性显著提升。对反应条件进行优化,在添加0.08 g KHCO3,氧化剂O2压力为1 MPa,反应温度为80℃,使用0.1 g Ru/NiFe_(2)O_(4)催化剂,在水溶液中反应12 h HMF能完全转化,2,5-呋喃二甲酸(FDCA)产率为98.1%。Ru/NiFe_(2)O_(4)循环使用5次后仍能保持较高的活性,催化剂上活性组分Ru不易浸出,并且催化剂具有磁性能便于与反应溶液分离。为今后工业化催化HMF高效选择性氧化合成FDCA提供参考。展开更多
文摘Novel graphitic carbon nitride(g-C_(3)N_(4))nanosheet/Bi_(5)O_(7)Br/NH_(2)-MIL-88B(Fe)photocatalysts(denoted as GCN-NSh/Bi_(5)O_(7)Br/FeMOF,in which MOF is metal–organic framework)with double S-scheme heterojunctions were synthesized by a facile solvothermal route.The resultant materials were examined by X-ray photoelectron spectrometer(XPS),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDX),transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),photoluminescence spectroscopy(PL),Fourier transform infrared spectroscopy(FT-IR),UV-Vis diffuse reflection spectroscopy(UV-vis DRS),photocurrent density,electrochemical impedance spectroscopy(EIS),and Brunauer–Emmett–Teller(BET)analyses.After the integration of Fe-MOF with GCN-NSh/Bi_(5)O_(7)Br,the removal constant of tetracycline over the optimal GCN-NSh/Bi_(5)O_(7)Br/Fe-MOF(15wt%)nanocomposite was promoted 33 times compared with that of the pristine GCN.The GCN-NSh/Bi_(5)O_(7)Br/Fe-MOF(15wt%)nanocomposite showed superior photoactivity to azithromycin,metronidazole,and cephalexin removal that was 36.4,20.2,and 14.6 times higher than that of pure GCN,respectively.Radical quenching tests showed that·O_(2)-and h+mainly contributed to the elimination reaction.In addition,the nanocomposite maintained excellent activity after 4 successive cycles.Based on the developed n–n heterojunctions among n-GCN-NSh,n-Bi_(5)O_(7)Br,and n-Fe-MOF semiconductors,the double S-scheme charge transfer mechanism was proposed for the destruction of the selected antibiotics.
文摘采用超声辅助室温原位沉淀法合成BC/Bi_(4)O_(5)Br_(2)光催化剂,在可见光下对比了TiO_(2)体系、BC/Bi_(4)O_(5)Br_(2)体系以及BC/Bi_(4)O_(5)Br_(2)耦合过一硫酸盐(PMS)体系处理渗滤液尾水的效果。考察了BC/Bi_(4)O_(5)Br_(2)耦合PMS体系中PMS投加量和反应时间的影响,通过紫外可见光谱、三维荧光图谱分析渗滤液尾水有机物成分。结果表明:BC/Bi_(4)O_(5)Br_(2)耦合PMS体系对腐殖质的去除效果较另外两体系的效果优异,BC/Bi_(4)O_(5)Br_(2)对COD、腐殖质(A_(254))、色度(CN)的去除率分别为13.07%、12.74%、52.19%,BOD_(5)/COD从0.08提升至0.18。BC/Bi_(4)O_(5)Br_(2)耦合PMS体系中,0.1 g BC/Bi_(4)O_(5)Br_(2)耦合0.20 g PMS体系对渗滤液尾水有机物有良好的降解效果,尤其在反应开始的前0.5 h作用效果明显,1.5 h后降解效率不再明显增加。BC/Bi_(4)O_(5)Br_(2)耦合PMS体系对TOC的最大去除率为30.5%,较BC/Bi_(4)O_(5)Br_(2)体系提高16.5%;对腐殖质的最大去除率为53.97%,较BC/Bi_(4)O_(5)Br_(2)体系提升41.5%。紫外可见光谱、三维荧光图谱表明渗滤液尾水以类腐殖质为主。研究结果可为非均相耦合过一硫酸盐光催化处理渗滤液尾水提供一定参考。
基金National Natural Science Foundation of China(12175254,U1832119)National Key R&D Program of China(2021YFE0104800)+2 种基金International Partnership Program of Chinese Academy of Sciences(121631KYSB20200039)International Cooperation Project of Shanghai Science and Technology Commission(20520750200)National Centre for Research and Development(WPC2/1/SCAPOL/2021)。
文摘采用水热-煅烧法制备了磁性镍铁尖晶石载体NiFe_(2)O_(4),再采用浸渍-还原法在载体上负载Ru纳米粒子制备Ru/NiFe_(2)O_(4)催化剂。采用X射线衍射(XRD)、N2吸附-脱附(BET)、NH3程序升温脱附(NH3-TPD)、H_(2)程序升温还原(H_(2)-TPR)、X射线光电子能谱(XPS)和电感耦合等离子体发射光谱(ICP-OES)测试对催化剂进行表征分析。结果表明,Ru/NiFe_(2)O_(4)催化剂表面氧物种丰富,相较于载体,负载Ru后催化剂比表面积和表面酸量增加,Ru与载体存在相互作用,这可能是催化剂高活性和高稳定性的关键。将催化剂用于5-羟甲基糠醛(HMF)的选择性氧化,负载Ru后,催化剂催化活性显著提升。对反应条件进行优化,在添加0.08 g KHCO3,氧化剂O2压力为1 MPa,反应温度为80℃,使用0.1 g Ru/NiFe_(2)O_(4)催化剂,在水溶液中反应12 h HMF能完全转化,2,5-呋喃二甲酸(FDCA)产率为98.1%。Ru/NiFe_(2)O_(4)循环使用5次后仍能保持较高的活性,催化剂上活性组分Ru不易浸出,并且催化剂具有磁性能便于与反应溶液分离。为今后工业化催化HMF高效选择性氧化合成FDCA提供参考。