A series of new biochar-supported composite based on the combination of biochar and metallic nanoparticles(NPs)were produced through single-step pyrolysis of FeCl_3–Ti(OBu)_4 laden agar biomass under NH_3 environment...A series of new biochar-supported composite based on the combination of biochar and metallic nanoparticles(NPs)were produced through single-step pyrolysis of FeCl_3–Ti(OBu)_4 laden agar biomass under NH_3 environment.The physiochemical properties of composites were characterized thoroughly.It has found that heating temperature and N-doping through NH_3-ambiance pyrolysis significantly influence the visible-light sensitivity and bandgap energy of composites.The catalytic activities of composites were measured by degradation of Methylene Blue(MB)in the presence or absence of H_2O_2 and visible-light irradiation.Our best catalyst(N–TiO_2–Fe_3O_4-biochar)exhibits rapid and high MB removal competency(99.99%)via synergism of adsorption,photodegradation,and Fenton-like reaction.Continuous production of O_2U^-and UOH radicles performs MB degradation and mineralization,confirmed by scavenging experiments and degradation product analysis.The local trap state Ti^(3+),Fe_3O_4,and N-carbon of the catalyst acted as active sites.It has suggested that the Ti^(3+)and N-doped dense carbon layer improve charge separation and shuttle that prolonged photo-Fenton like reaction.Moreover,the catalyst is highly stable,collectible,and recyclable up to 5 cycles with high MB degradation efficiency.This work provides a new insight into the synthesis of highly visible-light sensitized biocharsupported photocatalyst through NH_3-ambiance pyrolysis of NPs-laden biomass.展开更多
To understand the effect of a CO_(2)atmosphere on the properties of the transformation from fuel-N to NO_(x)precursors(mainly NH_(3)and HCN),pyrolysis experiment on Pingliang coal(PL coal),wheat straw and their corres...To understand the effect of a CO_(2)atmosphere on the properties of the transformation from fuel-N to NO_(x)precursors(mainly NH_(3)and HCN),pyrolysis experiment on Pingliang coal(PL coal),wheat straw and their corresponding blends was carried out in a fluidized bed reactor within a temperature range of 750℃to 850℃.The results indicated that the PL coal and wheat straw show different NO_(x)precursor formation properties owing to the discrepancy between the N-containing structures in the raw materials.Compared with an argon atmosphere,CO_(2)can effectively suppress the formation of NH_(3).For HCN,the HCN yield of PL coal is suppressed and the HCN yield of wheat straw is promoted.Furthermore,CO_(2)can suppress the overall nitrogen conversion rate of NH_(3)^(+)HCN for both coal and biomass,which causes more fuel-N to convert into tar-N and N_(2)-N.For the blends of PL coal and wheat straw,the copyrolysis synergistic effect of coal/biomass influences the selectivity of HCN and NH_(3).The copyrolysis synergistic effect favors the formation of copyrolyzed HCN but has an opposite impact on the transformation from fuel-N to NH_(3).The synergistic effect of coal/biomass promotes the overall nitrogen conversion rate of NH_(3)^(+)HCN under a CO_(2)atmosphere,and the overall nitrogen conversion rate of NH_(3)+HCN is suppressed under an argon atmosphere,conversely.In addition,the synergistic effect of coal/biomass suppresses the yield of environmentally harmless N_2,and more fuel-N was retained in the char.展开更多
基金supported by the National Basic Research Program of China (973 Program, 2014CB238903)the National Natural Science Foundation of China (Nos. 41672144, 41173032, and 41373110)
文摘A series of new biochar-supported composite based on the combination of biochar and metallic nanoparticles(NPs)were produced through single-step pyrolysis of FeCl_3–Ti(OBu)_4 laden agar biomass under NH_3 environment.The physiochemical properties of composites were characterized thoroughly.It has found that heating temperature and N-doping through NH_3-ambiance pyrolysis significantly influence the visible-light sensitivity and bandgap energy of composites.The catalytic activities of composites were measured by degradation of Methylene Blue(MB)in the presence or absence of H_2O_2 and visible-light irradiation.Our best catalyst(N–TiO_2–Fe_3O_4-biochar)exhibits rapid and high MB removal competency(99.99%)via synergism of adsorption,photodegradation,and Fenton-like reaction.Continuous production of O_2U^-and UOH radicles performs MB degradation and mineralization,confirmed by scavenging experiments and degradation product analysis.The local trap state Ti^(3+),Fe_3O_4,and N-carbon of the catalyst acted as active sites.It has suggested that the Ti^(3+)and N-doped dense carbon layer improve charge separation and shuttle that prolonged photo-Fenton like reaction.Moreover,the catalyst is highly stable,collectible,and recyclable up to 5 cycles with high MB degradation efficiency.This work provides a new insight into the synthesis of highly visible-light sensitized biocharsupported photocatalyst through NH_3-ambiance pyrolysis of NPs-laden biomass.
基金the financial support of the National Natural Science Foundation of China(Grant No.5141101283)。
文摘To understand the effect of a CO_(2)atmosphere on the properties of the transformation from fuel-N to NO_(x)precursors(mainly NH_(3)and HCN),pyrolysis experiment on Pingliang coal(PL coal),wheat straw and their corresponding blends was carried out in a fluidized bed reactor within a temperature range of 750℃to 850℃.The results indicated that the PL coal and wheat straw show different NO_(x)precursor formation properties owing to the discrepancy between the N-containing structures in the raw materials.Compared with an argon atmosphere,CO_(2)can effectively suppress the formation of NH_(3).For HCN,the HCN yield of PL coal is suppressed and the HCN yield of wheat straw is promoted.Furthermore,CO_(2)can suppress the overall nitrogen conversion rate of NH_(3)^(+)HCN for both coal and biomass,which causes more fuel-N to convert into tar-N and N_(2)-N.For the blends of PL coal and wheat straw,the copyrolysis synergistic effect of coal/biomass influences the selectivity of HCN and NH_(3).The copyrolysis synergistic effect favors the formation of copyrolyzed HCN but has an opposite impact on the transformation from fuel-N to NH_(3).The synergistic effect of coal/biomass promotes the overall nitrogen conversion rate of NH_(3)^(+)HCN under a CO_(2)atmosphere,and the overall nitrogen conversion rate of NH_(3)+HCN is suppressed under an argon atmosphere,conversely.In addition,the synergistic effect of coal/biomass suppresses the yield of environmentally harmless N_2,and more fuel-N was retained in the char.
