针对AZ31镁合金作为镁电池负极时存在自腐蚀速率大、阳极极化、电位滞后等问题,寻找合适的缓蚀剂及其用量调配电解液以提高电池的放电性能。通过腐蚀浸泡试验表征了缓蚀剂Li_(2)CrO_(4)的缓蚀效果,然后通过极化曲线、电化学阻抗谱研究了...针对AZ31镁合金作为镁电池负极时存在自腐蚀速率大、阳极极化、电位滞后等问题,寻找合适的缓蚀剂及其用量调配电解液以提高电池的放电性能。通过腐蚀浸泡试验表征了缓蚀剂Li_(2)CrO_(4)的缓蚀效果,然后通过极化曲线、电化学阻抗谱研究了Mg(ClO_(4))_(2)溶液中Li_(2)CrO_(4)用量对AZ31镁合金电化学性能的影响,最后通过组装水系镁锰电池进行恒流放电作为应用端测试。结果表明:Li_(2)CrO_(4)能够使AZ31镁合金的腐蚀电位正移,最大正移量达到150 m V,在水系镁锰电池应用中能够提高镁电池的放电平台,当Li_(2)CrO_(4)质量分数为0.7%时放电平台提高0.15 V左右;当Li_(2)CrO_(4)质量分数为1.2%时,其能够显著改善AZ31镁合金在Mg(ClO_(4))_(2)溶液中的腐蚀,水系镁锰电池放电容量达最大,为196.9 m A·h,相对空白溶液,电池的放电容量提高约64%,工作电压高达1.39 V且放电曲线稳定。展开更多
To realize the high-efficiency photodegradation of antibiotics,a novel S-scheme heterojunction photocatalyst g-C_(3)N_(4)/Bi_(8)(CrO_(4))O_(11) was proposed and successfully prepared in this work.The 10%g-C_(3)N_(4)/B...To realize the high-efficiency photodegradation of antibiotics,a novel S-scheme heterojunction photocatalyst g-C_(3)N_(4)/Bi_(8)(CrO_(4))O_(11) was proposed and successfully prepared in this work.The 10%g-C_(3)N_(4)/Bi_(8)(CrO_(4))O_(11) heterojunction exhibits the highest degradation rate of norfloxacin(NOR)and bisphenol A(BPA).The degradation rate of NOR on 10%g-C_(3)N_(4)/Bi_(8)(CrO_(4))O_(11) is about 1.38 and 2.33 times higher than that of pure Bi_(8)(CrO_(4))O_(11) and g-C_(3)N_(4),respectively.Further,the degradation rate of BPA over 10%g-C_(3)N_(4)/Bi_(8)(CrO_(4))O_(11) heterojunction is bout 1.35 and 9.11 times higher than that of pure Bi_(8)(CrO_(4))O_(11) and g-C_(3)N_(4),respectively.The formation of S-scheme heterojunction facilitates the separation of photogenerated electron-hole pairs and reduces the recombination of charge carriers,which was confirmed by photocurrent,electrochemical impedance spectroscopy,steady-state and time-resolved transient photoluminescence spectrum,etc.The in-situ X-ray photoelectron spectroscopy,radical trapping experiments and electron paramagnetic resonance results demonstrate that the charge transfer is in accord with S-scheme mechanism.展开更多
Developing non‐noble‐metal electrocatalyst with efficient and durable activity is a urgent task for addressing the sluggish reaction kinetics of electrochemical water oxidation.Structural evolution of the electrocat...Developing non‐noble‐metal electrocatalyst with efficient and durable activity is a urgent task for addressing the sluggish reaction kinetics of electrochemical water oxidation.Structural evolution of the electrocatalyst is an important strategy for achieving enhanced performance.Herein,in situ evolution of surface Co_(2)CrO_(4) to CoOOH/CrOOH(CoOOH/CrOOH‐Co_(2)CrO_(4))by an electrochemical method under alkaline conditions was designed for enhancing the electrocatalytic performance of water oxidation.The experiments demonstrated that the synergy between CoOOH/CrOOH and Co_(2)CrO_(4) resulted in a marked increase in the number of active sites and improved the rate of charge transfer,which enhanced the activity for water oxidation.At a geometrical current density of 20 mA cm^(−2),the overpotential of the oxygen evolution reaction was 244 mV and the turnover frequency was 0.536 s^(−1) in 1.0 M NaOH.展开更多
Sulfosalicylic acid(SSA) was used as an intercalation agent and an excellent antenna to synthesize layered rare-earth hydroxide(LRH) materials and directly obtain SSA-modified terbium-doped ytterbium hydroxide nanoshe...Sulfosalicylic acid(SSA) was used as an intercalation agent and an excellent antenna to synthesize layered rare-earth hydroxide(LRH) materials and directly obtain SSA-modified terbium-doped ytterbium hydroxide nanosheets by mechanical exfoliation. The crystal structure and morphologies of the LRHs and nanosheets were determined by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The particle size and zeta potential of the prepared nanosheets were also analyzed. The as-prepared nanosheets exhibited excellent luminescent properties. The positively charged nanosheets were electrophoretically deposited on a conductive glass to form a thin film. The luminescence of this thin film can be quenched by chromate(CrO_4^(2–)) and bilirubin(BR), which shows good sensing properties. The quenching mechanism of the sensing film by CrO_4^(2–) and BR was discussed based on the spectra and structure of the film.展开更多
文摘针对AZ31镁合金作为镁电池负极时存在自腐蚀速率大、阳极极化、电位滞后等问题,寻找合适的缓蚀剂及其用量调配电解液以提高电池的放电性能。通过腐蚀浸泡试验表征了缓蚀剂Li_(2)CrO_(4)的缓蚀效果,然后通过极化曲线、电化学阻抗谱研究了Mg(ClO_(4))_(2)溶液中Li_(2)CrO_(4)用量对AZ31镁合金电化学性能的影响,最后通过组装水系镁锰电池进行恒流放电作为应用端测试。结果表明:Li_(2)CrO_(4)能够使AZ31镁合金的腐蚀电位正移,最大正移量达到150 m V,在水系镁锰电池应用中能够提高镁电池的放电平台,当Li_(2)CrO_(4)质量分数为0.7%时放电平台提高0.15 V左右;当Li_(2)CrO_(4)质量分数为1.2%时,其能够显著改善AZ31镁合金在Mg(ClO_(4))_(2)溶液中的腐蚀,水系镁锰电池放电容量达最大,为196.9 m A·h,相对空白溶液,电池的放电容量提高约64%,工作电压高达1.39 V且放电曲线稳定。
文摘To realize the high-efficiency photodegradation of antibiotics,a novel S-scheme heterojunction photocatalyst g-C_(3)N_(4)/Bi_(8)(CrO_(4))O_(11) was proposed and successfully prepared in this work.The 10%g-C_(3)N_(4)/Bi_(8)(CrO_(4))O_(11) heterojunction exhibits the highest degradation rate of norfloxacin(NOR)and bisphenol A(BPA).The degradation rate of NOR on 10%g-C_(3)N_(4)/Bi_(8)(CrO_(4))O_(11) is about 1.38 and 2.33 times higher than that of pure Bi_(8)(CrO_(4))O_(11) and g-C_(3)N_(4),respectively.Further,the degradation rate of BPA over 10%g-C_(3)N_(4)/Bi_(8)(CrO_(4))O_(11) heterojunction is bout 1.35 and 9.11 times higher than that of pure Bi_(8)(CrO_(4))O_(11) and g-C_(3)N_(4),respectively.The formation of S-scheme heterojunction facilitates the separation of photogenerated electron-hole pairs and reduces the recombination of charge carriers,which was confirmed by photocurrent,electrochemical impedance spectroscopy,steady-state and time-resolved transient photoluminescence spectrum,etc.The in-situ X-ray photoelectron spectroscopy,radical trapping experiments and electron paramagnetic resonance results demonstrate that the charge transfer is in accord with S-scheme mechanism.
文摘Developing non‐noble‐metal electrocatalyst with efficient and durable activity is a urgent task for addressing the sluggish reaction kinetics of electrochemical water oxidation.Structural evolution of the electrocatalyst is an important strategy for achieving enhanced performance.Herein,in situ evolution of surface Co_(2)CrO_(4) to CoOOH/CrOOH(CoOOH/CrOOH‐Co_(2)CrO_(4))by an electrochemical method under alkaline conditions was designed for enhancing the electrocatalytic performance of water oxidation.The experiments demonstrated that the synergy between CoOOH/CrOOH and Co_(2)CrO_(4) resulted in a marked increase in the number of active sites and improved the rate of charge transfer,which enhanced the activity for water oxidation.At a geometrical current density of 20 mA cm^(−2),the overpotential of the oxygen evolution reaction was 244 mV and the turnover frequency was 0.536 s^(−1) in 1.0 M NaOH.
文摘Sulfosalicylic acid(SSA) was used as an intercalation agent and an excellent antenna to synthesize layered rare-earth hydroxide(LRH) materials and directly obtain SSA-modified terbium-doped ytterbium hydroxide nanosheets by mechanical exfoliation. The crystal structure and morphologies of the LRHs and nanosheets were determined by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The particle size and zeta potential of the prepared nanosheets were also analyzed. The as-prepared nanosheets exhibited excellent luminescent properties. The positively charged nanosheets were electrophoretically deposited on a conductive glass to form a thin film. The luminescence of this thin film can be quenched by chromate(CrO_4^(2–)) and bilirubin(BR), which shows good sensing properties. The quenching mechanism of the sensing film by CrO_4^(2–) and BR was discussed based on the spectra and structure of the film.
