Porous graphitic carbon nitride（pg-C3N4） nanosheets have been prepared through a one-step ammonia thermopolymerization method.The effects of synthetic temperature on the structural,optical and photocatalytic propert...Porous graphitic carbon nitride（pg-C3N4） nanosheets have been prepared through a one-step ammonia thermopolymerization method.The effects of synthetic temperature on the structural,optical and photocatalytic properties of the samples have been investigated.Characterization results show that the heptazine-based conjugate heterocyclic structure was formed over 500℃,which is attributed to the inhibitory effect of ammonia from the decomposition of NH4SCN.Precise nanosheet morphology and an increased pore distribution with an enlarged surface area are observed for the samples obtained under high temperatures.Optical analysis results show that the bandgap of the samples widens and photoluminescene intensity is gradually quenched as the treating temperature is increased.The results demonstrate that a higher polymerization temperature improves the nanolayer structure,porosity and migration rate of the photo-induced carriers of the samples.The pg-C3N4 nanosheets prepared at 600℃ presents the highest photocatalytic activity for hydrogen evolution from water under visible-light irradiation.This study demonstrates a novel strategy for the synthesis and optimization of polymer semiconductor nanosheets with gratifying photocatalytic performance.展开更多
Layered double Mg-Fe-CO3 hydroxide （Mg-Fe-LDH） with a mole ratio of Mg to Fe of 3 was synthesized by coprecipitation method and calcined product Mg-Fe-CLDH was obtained by heating Mg-Fe-LDH at 500 ℃ for 6 h. The as...Layered double Mg-Fe-CO3 hydroxide （Mg-Fe-LDH） with a mole ratio of Mg to Fe of 3 was synthesized by coprecipitation method and calcined product Mg-Fe-CLDH was obtained by heating Mg-Fe-LDH at 500 ℃ for 6 h. The as prepared Mg-Fe-LDH and calcined Mg-Fe-CLDH were used for removal of glutamic acid （Glu） from aqueous solution, respectively. Batch studies were carried out to address various experimental parameters such as contact time, pH, initial glutamic acid （Glu） concentration, co-existing anions and temperature. Glu was removed effectively （99.9%） under the optimized experimental conditions with Mg-Fe-CLDH. The adsorption kinetics follows the Ho’s pseudo second-order model. Isotherms for adsorption with Mg-Fe-CLDH at different solution temperatures were well described using the Langmuir model with a good correlation coefficient. The intraparticle diffusion model fitted the data well, which suggests that the intraparticle diffusion is not only the rate-limiting step.展开更多
Hydrogenation and ammoniation of SrTiOa （STO）, a normal ultraviolet photocatalyst, were performed by annealing STO（100） in Hz：N2=5%：95% and NH3, respectively, at various temperatures T. It was found that hydroge...Hydrogenation and ammoniation of SrTiOa （STO）, a normal ultraviolet photocatalyst, were performed by annealing STO（100） in Hz：N2=5%：95% and NH3, respectively, at various temperatures T. It was found that hydrogenation at T≥900℃ remarkably enhanced the UV photocatalytic ability of STO, but the visible-light photocatalysis was still unavailable, while ammoniation at T≥800℃ introduced the N doping, resulting in visible-light photocat- alytie activity. Furthermore, when a hydrogenated STO was subjected to ammoniation, the visible-light photocatalytie ability was nearly the same as that of the ammoniated one; but the hydrogenation of an ammoniated one significantly enhanced visible-light photoeatalysis, indicating a synergetic effect of hydrogenation and ammoniation. Discussions and identifications have been made to analyze these results.展开更多
Liquid chemical hydrides, which store hydrogen in the form of chemical bonds, are considered one of the most promising classes of hydrogen storage materials. Their application depends heavily on the development of eff...Liquid chemical hydrides, which store hydrogen in the form of chemical bonds, are considered one of the most promising classes of hydrogen storage materials. Their application depends heavily on the development of efficient catalytic systems. Gold‐containing metal nanoparticles have exhibited excellent catalytic performance for hydrogen generation from liquid chemical hydrides. The present mini‐review focuses on recent developments in hydrogen generation from liquid chemical hydrides using gold‐nanoparticle and gold‐containing heterometallic nanoparticle catalysts.展开更多
[Objective] To find out the process conditions and influence factors for the biotreatment of odor gases of hydrogen sulfide（H2S） and ammonia（NH3）. [Method]The degradation performances on H2 S and NH3 were investig...[Objective] To find out the process conditions and influence factors for the biotreatment of odor gases of hydrogen sulfide（H2S） and ammonia（NH3）. [Method]The degradation performances on H2 S and NH3 were investigated during the start-up and stable operation process of biofilter with ceramsites as the packing microorganisms. [Result] The biofilm formation of the biofilter system to purify the waste gas of H2 S was completed within 9 d, and the removal rate of H2 S could reach up to 99% with the initial concentration of 100-1 000 mg/m^3 and empty bed residence time（EBRT） of142-290 s. The biofilm formation of the biofilter system to purify the waste gas of NH3 was completed within 10 d with the removal rate reaching up to 94.61%.[Conclusion] Under suitable conditions, the biofilter showed high removal rates to both H2 S and NH3.展开更多
Aluminium hydroxide precipitation from synthetic sodium aluminate solution was studied in the presence of hydrazine or hydrogen peroxide. The addition of low concentration of hydrazine is found to be effective, while ...Aluminium hydroxide precipitation from synthetic sodium aluminate solution was studied in the presence of hydrazine or hydrogen peroxide. The addition of low concentration of hydrazine is found to be effective, while higher amount of hydrogen peroxide is required to generate similar effect. XRD data confirm the product phase to be gibbsitic by nature. The scanning electron micrographs （SEM） show that agglomerated products form in the presence of hydrazine while fine discrete particles are produced with hydrogen peroxide. The probable mechanism of precipitation in the presence of hydrazine and hydrogen peroxide is also discussed.展开更多
基金supported by the National Natural Science Foundation of China(21503096)the Natural Science Foundation of Jiangsu Province(BK20140507)~~
文摘Porous graphitic carbon nitride（pg-C3N4） nanosheets have been prepared through a one-step ammonia thermopolymerization method.The effects of synthetic temperature on the structural,optical and photocatalytic properties of the samples have been investigated.Characterization results show that the heptazine-based conjugate heterocyclic structure was formed over 500℃,which is attributed to the inhibitory effect of ammonia from the decomposition of NH4SCN.Precise nanosheet morphology and an increased pore distribution with an enlarged surface area are observed for the samples obtained under high temperatures.Optical analysis results show that the bandgap of the samples widens and photoluminescene intensity is gradually quenched as the treating temperature is increased.The results demonstrate that a higher polymerization temperature improves the nanolayer structure,porosity and migration rate of the photo-induced carriers of the samples.The pg-C3N4 nanosheets prepared at 600℃ presents the highest photocatalytic activity for hydrogen evolution from water under visible-light irradiation.This study demonstrates a novel strategy for the synthesis and optimization of polymer semiconductor nanosheets with gratifying photocatalytic performance.
基金Project(21176263)supported by the National Natural Science Foundation of China
文摘Layered double Mg-Fe-CO3 hydroxide （Mg-Fe-LDH） with a mole ratio of Mg to Fe of 3 was synthesized by coprecipitation method and calcined product Mg-Fe-CLDH was obtained by heating Mg-Fe-LDH at 500 ℃ for 6 h. The as prepared Mg-Fe-LDH and calcined Mg-Fe-CLDH were used for removal of glutamic acid （Glu） from aqueous solution, respectively. Batch studies were carried out to address various experimental parameters such as contact time, pH, initial glutamic acid （Glu） concentration, co-existing anions and temperature. Glu was removed effectively （99.9%） under the optimized experimental conditions with Mg-Fe-CLDH. The adsorption kinetics follows the Ho’s pseudo second-order model. Isotherms for adsorption with Mg-Fe-CLDH at different solution temperatures were well described using the Langmuir model with a good correlation coefficient. The intraparticle diffusion model fitted the data well, which suggests that the intraparticle diffusion is not only the rate-limiting step.
文摘Hydrogenation and ammoniation of SrTiOa （STO）, a normal ultraviolet photocatalyst, were performed by annealing STO（100） in Hz：N2=5%：95% and NH3, respectively, at various temperatures T. It was found that hydrogenation at T≥900℃ remarkably enhanced the UV photocatalytic ability of STO, but the visible-light photocatalysis was still unavailable, while ammoniation at T≥800℃ introduced the N doping, resulting in visible-light photocat- alytie activity. Furthermore, when a hydrogenated STO was subjected to ammoniation, the visible-light photocatalytie ability was nearly the same as that of the ammoniated one; but the hydrogenation of an ammoniated one significantly enhanced visible-light photoeatalysis, indicating a synergetic effect of hydrogenation and ammoniation. Discussions and identifications have been made to analyze these results.
基金supported by Ministry of Economy, Trade and Industry (METI)National Institute of Advanced Industrial Science Technology (AIST) and Kobe University
文摘Liquid chemical hydrides, which store hydrogen in the form of chemical bonds, are considered one of the most promising classes of hydrogen storage materials. Their application depends heavily on the development of efficient catalytic systems. Gold‐containing metal nanoparticles have exhibited excellent catalytic performance for hydrogen generation from liquid chemical hydrides. The present mini‐review focuses on recent developments in hydrogen generation from liquid chemical hydrides using gold‐nanoparticle and gold‐containing heterometallic nanoparticle catalysts.
基金Supported by the Climbing Program for Graduates of Guangdong Province~~
文摘[Objective] To find out the process conditions and influence factors for the biotreatment of odor gases of hydrogen sulfide（H2S） and ammonia（NH3）. [Method]The degradation performances on H2 S and NH3 were investigated during the start-up and stable operation process of biofilter with ceramsites as the packing microorganisms. [Result] The biofilm formation of the biofilter system to purify the waste gas of H2 S was completed within 9 d, and the removal rate of H2 S could reach up to 99% with the initial concentration of 100-1 000 mg/m^3 and empty bed residence time（EBRT） of142-290 s. The biofilm formation of the biofilter system to purify the waste gas of NH3 was completed within 10 d with the removal rate reaching up to 94.61%.[Conclusion] Under suitable conditions, the biofilter showed high removal rates to both H2 S and NH3.
基金M/s NALCO, Bhubaneswar for the partial financial support to carry out this work
文摘Aluminium hydroxide precipitation from synthetic sodium aluminate solution was studied in the presence of hydrazine or hydrogen peroxide. The addition of low concentration of hydrazine is found to be effective, while higher amount of hydrogen peroxide is required to generate similar effect. XRD data confirm the product phase to be gibbsitic by nature. The scanning electron micrographs （SEM） show that agglomerated products form in the presence of hydrazine while fine discrete particles are produced with hydrogen peroxide. The probable mechanism of precipitation in the presence of hydrazine and hydrogen peroxide is also discussed.
