过渡金属硫化物相关电催化剂的设计与应用研究

Recent progress on design and applications of transition metal chalcogenide-associated electrocatalysts for the overall water splitting

自从国际社会提出“碳达峰、碳中和”目标以来,人们越来越意识到节约资源、保护环境、开发新能源的必要性.氢能(H_(2))作为最具竞争力的清洁能源之一,引起了研究人员的广泛关注.电化学全解水被认为是一种利用风能和太阳能产生氢气的有效技术,其主要由两个半反应组成:析氧反应(OER)和析氢反应(HER).然而,在实际工业化生产过程中阳极反应动力学OER慢,能量转换效率低,阴极反应稳定性差,导致经济效益不理想,因此,急需开发和探索耐久高效的电催化剂.过渡金属硫化物因具有独特的结构特征、丰富的活性位点和可调控的电子性质和组成,而被广泛用于电化学全解水制氢.本文综述了过渡金属硫化物的合成方法,一般包括:水热(溶剂热)法、电化学沉积法、液相剥离法、化学气相沉积法和球磨法,并概述了不同方法的基本概念、合成步骤以及优缺点.总结了近年用于电催化领域中典型单一硫化物(包括MoS_(2),WS_(2),Co3S_(4),Ni_(3)S_(2)等)材料的合成方法和机理,明确了S元素在整个电催化过程中的重要作用.针对单一硫化物稳定性差、活性位点少、电化学活性不高的缺点,详细总结了双金属、多金属以及单原子、双原子硫化物的催化机理和催化性能.当采用复合、引入缺陷、空缺和形态调节等手段修饰时,能够有效调控金属硫化物的电子结构,增加活性位点数量,优化反应中间体的吸附能,降低OER过程的能垒,从而使多金属硫化物具有优异的电化学性能.最后,通过一些典型的研究结果揭示了过渡金属硫化物在水分子分裂过程中的结构特性变化原理,特别是对于多金属硫化物,活性位点可以是金属阳离子,而其他金属的引入将在一定程度上改变活性中心附近的电子结构和配位环境,进而改善材料的催化性能.尽管过渡金属硫化物在电催化领域的应用研究取得了一系列进展,但仍存在诸多挑战,距实际应用仍有较大差距.需要综合考虑经济、高性能、稳定性和环境友好等因素进行过渡金属硫化物催化材料的设计、制备和性能调控,并为大规模应用提供基础.同时,深入探索电催化机理有利于设计高效电催化剂和推动电催化领域的持续发展.综上,本文为新型电催化材料的制备和电催化全解水机理的深入研究提供一定的参考.

Electrochemical hydrogen evolution via water splitting has been regarded as a highly promising technique for fossil-fuel substitution in the future to avoid environmental pollution and energy waste.As half of the water splitting reaction,the oxygen evolution reaction(OER)is the major obstacle because of the sluggish kinetics of the complex reaction.It is imperative and urgent to develop highly efficient,low cost and earth-abundant electrocatalysts to overcome the sluggish kinetics issue.Among the various non-noble-metal-based electrocatalysts,transition metal chalcogenide(TMS)associated materials have been exploited as potential candidates for the past few years due to their excellent electrochemical performance and unique internal structure.In this review,we have summarized the recent advances of transition metal sulfides(TMSs)for hydrogen evolution reaction(HER),OER,and overall water splitting,then we have reviewed several modified strategies from the perspective of their functional concepts to synthesis methods,characterization techniques,catalytic mechanisms and performances.Finally,the existing deficiencies,challenges and future development directions of TMSs in OER,HER,and overall water splitting process are further discussed and summarized.