【摘要】 Mo₂C MXene（Mo₂CT_x）由于其表面Mo活性位点具有类Pt的电子结构在光催化中展现出优异的析氢潜力。然而，Mo₂CT_x中的Mo位点在析氢反应（HER）过程中通常表现出过强的H吸附能力，显著限制了Mo₂CT_x的本征催化活性。为了削弱Mo活性位点的H吸附能力，本论文通过功函数诱导效应原位构建MoC-Mo₂C MXene异质结，实现了d轨道电子的调控。利用Co诱导的熔盐法将Mo₂C MXene原位转化为MoC，随后通过简单的超声辅助方法与TiO₂耦合，制备了MoCMo₂CT_x/TiO₂光催化剂。光催化产氢测试表明，最优的MoC-Mo₂CT_x/TiO₂样品实现了1886μmol·h^-1·g^-1的产氢速率，分别是TiO₂和Mo₂CF_x/TiO₂（Mo₂CF_x通过常规蚀刻剂NH₄F+HCl制备）的117.9倍和3.9倍。实验和理论计算证实，MoC与Mo₂C MXene之间的功函数梯度诱导电子从MoC向Mo₂C MXene转移，从而削弱了Mo₂CT_x助催化剂中Mo活性位点的H吸附能力，进而提升了其HER活性。该研究为原位构建基于Mo₂C MXene的异质结以调控Mo活性位点的H吸附能力提供了一种新策略。更多还原

【Abstract】 Mo₂C MXene （Mo₂CT_x） exhibits exceptional hydrogen-evolution potential in photocatalysis due to the Pt-like electronic structure of surface Mo active sites.However,the Mo sites in Mo₂CT_x usually show excessively strong H-adsorption during HER,significantly limiting the intrinsic catalytic activity of Mo₂CT_x.To weaken the H-adsorption capacity of Mo active sites,a strategy of modulating d-orbital electron is implemented via in-situ constructing MoC-Mo₂C MXene heterojunction by a work-function-induced effect.The Mo C-Mo₂CT_x heterojunction was synthesized by in situ conversion of Mo₂C MXene into MoC via a Co-induced molten salt method,followed by coupling with TiO₂ through a simple ultrasonication-assisted method to prepare the Mo C-Mo₂CT_x/Ti O₂ photocatalyst.Photocatalytic tests showed that the optimal MoC-Mo₂CT_x/TiO₂ sample achieves an excellent hydrogen production rate of 1886μmol·h^-1·g^-1,representing 117.9and 3.9 fold enhancements over Ti O₂ and Mo₂CF_X/TiO₂ （Mo₂CF₂ prepared by a conventional etchant NH₄F+HCl）,respectively.Experimental and theoretical calculations substantiate that the work-function gradient between Mo C and Mo₂C MXene induces electron transfer from MoC to Mo₂C MXene to weaken the H-adsorption of Mo active sites in Mo₂CT_x cocatalyst,thereby enhancing its HER activity.This research provides a new strategy of in situ constructing Mo₂C MXenebased heterojunction for adjusting the H-adsorption capacity of Mo active sites.更多还原