电解水技术是一种生产高纯氢燃料的方法,能够增强可再生能源发电系统的消纳能力.相较于质子交换膜(PEM)电解槽,碱性(ALK)电解槽可以使用非贵金属基催化电极,拥有更高的经济效益和市场占有率.然而,由于ALK电解槽处于质子稀缺环境,阴极氢...电解水技术是一种生产高纯氢燃料的方法,能够增强可再生能源发电系统的消纳能力.相较于质子交换膜(PEM)电解槽,碱性(ALK)电解槽可以使用非贵金属基催化电极,拥有更高的经济效益和市场占有率.然而,由于ALK电解槽处于质子稀缺环境,阴极氢气演化反应(HER)动力学变得更加复杂,需要快速解离水分子提供动态质子微环境.硫化钼(MoS_(2))纳米片边缘具有合适的质子吸附和演化的活性位点,是制备HER催化剂的潜力材料.但其二维基面原子由于配位饱和,显示出较弱的质子吸附能力.如何调控MoS_(2)基面以实现水解动力与质子吸附演化动力的集成,提升MoS_(2)纳米片的碱性HER活性,具有重要的科学和应用意义.本文提出了一种Co/O双原子植入策略,精准调控双活性位点及其电子结构,实现了水解离动力和质子吸附演化动力的高效耦联.首先,利用刻蚀和电沉积的两步实验法,在MoS_(2)基面上成功引入O和Co原子;随后,结合高分辨透射电镜、高角环形暗场-扫描透射电子显微镜、同步辐射X射线吸收精细结构谱等表征分析技术,精准识别了掺杂Co/O原子的位置和配位情况:O原子替换部分S原子,Co原子占据Mo原子的上方,构建出立体凸起的“O-Co-S_(2)”配位构型.催化在线的原位表征分析结果表明:该独特的“O-Co-S_(2)”原子基序发挥着水解离与氢演化反应协同催化效应.密度泛函理论计算结果也证实了该协同机制,其中Co位点促进水的解离反应,而S位点则有助于质子的转化生成氢气.因此,Co/O掺杂MoS_(2)催化剂(Co-O@MoS_(2))表现出较好的碱性HER活性:仅需81 mV的过电位,即可达到100 mA cm^(‒2)的电流密度,Tafel斜率低至42 mV dec^(‒1),在600 mA cm^(‒2)的高电流密度测试中运行300 h活性无衰减.上述碱性HER性能不仅远高于原始的MoS_(2)纳米片,而且也领先于部分已报道结果.综上所述,本文在MoS_(2)基面上构筑了原子级协同催化活性中心,显著促进了碱性HER反应性能,为原子活化工程开发先进催化剂提供参考,在原子级基序构造、表征和功能分析方面提供借鉴.展开更多
The use of single-atom cocatalysts plays a crucial role in enhancing artificial photocatalysis,where the precise construction of stable and efficient single-atom configuration is essential but remains challenging.Here...The use of single-atom cocatalysts plays a crucial role in enhancing artificial photocatalysis,where the precise construction of stable and efficient single-atom configuration is essential but remains challenging.Here,we report a simple one-step hydrothermal method for preparing single-atomic Mo modified ZnIn_(2)S_(4)(Mo-ZIS)nanosheets as a highly active photocatalytic hydrogen evolution(PHE)photocatalyst.The Mo substituting for portion of In atoms in ZIS nanosheets induces the spatial charge redistribution,which not only promotes the separation of photogenerated charge carriers but also optimizes the Gibbs free energy of adsorbing H*on S atoms at basal planes.As a result,Mo-ZIS exhibits an impressive PHE rate as high as 6.71 mmol·g^(−1)·h^(−1),over 10 times that of the pristine ZIS,with an apparent quantum efficiency(AQE)up to 38.8%at 420 nm.This study gains insights into the coordination configuration and electronic modulation resulting from single-atomic decoration,providing mechanistic cognitions for the development of advanced photocatalysts via non-precious metal atomic modification.展开更多
文摘电解水技术是一种生产高纯氢燃料的方法,能够增强可再生能源发电系统的消纳能力.相较于质子交换膜(PEM)电解槽,碱性(ALK)电解槽可以使用非贵金属基催化电极,拥有更高的经济效益和市场占有率.然而,由于ALK电解槽处于质子稀缺环境,阴极氢气演化反应(HER)动力学变得更加复杂,需要快速解离水分子提供动态质子微环境.硫化钼(MoS_(2))纳米片边缘具有合适的质子吸附和演化的活性位点,是制备HER催化剂的潜力材料.但其二维基面原子由于配位饱和,显示出较弱的质子吸附能力.如何调控MoS_(2)基面以实现水解动力与质子吸附演化动力的集成,提升MoS_(2)纳米片的碱性HER活性,具有重要的科学和应用意义.本文提出了一种Co/O双原子植入策略,精准调控双活性位点及其电子结构,实现了水解离动力和质子吸附演化动力的高效耦联.首先,利用刻蚀和电沉积的两步实验法,在MoS_(2)基面上成功引入O和Co原子;随后,结合高分辨透射电镜、高角环形暗场-扫描透射电子显微镜、同步辐射X射线吸收精细结构谱等表征分析技术,精准识别了掺杂Co/O原子的位置和配位情况:O原子替换部分S原子,Co原子占据Mo原子的上方,构建出立体凸起的“O-Co-S_(2)”配位构型.催化在线的原位表征分析结果表明:该独特的“O-Co-S_(2)”原子基序发挥着水解离与氢演化反应协同催化效应.密度泛函理论计算结果也证实了该协同机制,其中Co位点促进水的解离反应,而S位点则有助于质子的转化生成氢气.因此,Co/O掺杂MoS_(2)催化剂(Co-O@MoS_(2))表现出较好的碱性HER活性:仅需81 mV的过电位,即可达到100 mA cm^(‒2)的电流密度,Tafel斜率低至42 mV dec^(‒1),在600 mA cm^(‒2)的高电流密度测试中运行300 h活性无衰减.上述碱性HER性能不仅远高于原始的MoS_(2)纳米片,而且也领先于部分已报道结果.综上所述,本文在MoS_(2)基面上构筑了原子级协同催化活性中心,显著促进了碱性HER反应性能,为原子活化工程开发先进催化剂提供参考,在原子级基序构造、表征和功能分析方面提供借鉴.
基金financially supported by the National Natural Science Foundation of China(Nos.11974303 and 12074332)the Qinglan Project(No.337050073)of Jiangsu Province+2 种基金the High-End Talent Program(No.137080210)the Yangzhou University Interdisciplinary Research Project of Chemistry Discipline(No.yzuxk202014)the Innovative Science and Technology Platform Project of Cooperation between Yangzhou City and Yangzhou University(No.YZ2020263).
文摘The use of single-atom cocatalysts plays a crucial role in enhancing artificial photocatalysis,where the precise construction of stable and efficient single-atom configuration is essential but remains challenging.Here,we report a simple one-step hydrothermal method for preparing single-atomic Mo modified ZnIn_(2)S_(4)(Mo-ZIS)nanosheets as a highly active photocatalytic hydrogen evolution(PHE)photocatalyst.The Mo substituting for portion of In atoms in ZIS nanosheets induces the spatial charge redistribution,which not only promotes the separation of photogenerated charge carriers but also optimizes the Gibbs free energy of adsorbing H*on S atoms at basal planes.As a result,Mo-ZIS exhibits an impressive PHE rate as high as 6.71 mmol·g^(−1)·h^(−1),over 10 times that of the pristine ZIS,with an apparent quantum efficiency(AQE)up to 38.8%at 420 nm.This study gains insights into the coordination configuration and electronic modulation resulting from single-atomic decoration,providing mechanistic cognitions for the development of advanced photocatalysts via non-precious metal atomic modification.
