【作者】 刘芳格； 洪流； 杨成；

【Author】 Fangge Liu;Liu Hong;Cheng Yang;The Key Laboratory of synthetic and Biological Colloids,Ministry of Education,School of Chemical and Material Engineering,Jiangnan University;

【机构】 合成与生物胶体教育部重点实验室江南大学化学与材料工程学院；

【摘要】 用于电还原二氧化碳（CO₂RR）的催化剂主要集中在贵金属或碳材料,但由于贵金属的稀缺性和高成本以及碳材料的低选择性,需要更多的研究致力于其催化剂的开发与应用。二硫化钼（MoS₂）是一种带隙为1.8 e V的片层半导体材料,但易团聚导致活性位点较少,硫化铜的加入,可以改变其电子结构,增强其催化性能。本文报告了一种CuS@MoS₂复合纳米材料的简易且形貌可控的制备方法。以Cu纳米线为模板,采用一锅式溶剂热法制备CuS@MoS₂复合材料,其中MoS₂的沉积和铜的硫化同时发生。更重要的是,我们通过调节溶剂的分配和前驱体的比例,成功实现了包括纳米棒（NR）,分级中空（HHNS）和实心纳米球（SNS）在内的复合材料的形貌可控制备。当反应体系中乙醇的比例较低时,形成高度有序的棒状形态;随着乙醇/水比率的增加,溶剂极性降低,Cu S的形成需要更长的时间,铜纳米线将其自身弯曲成螺旋环束,MoS₂沉积在其表面,形成多层分级中空结构;随着Cu纳米线的剂量增加,螺旋束的间隙收缩,使得弯曲的CuS@MoS₂彼此融合以形成实心球形态。初步结果表明,棒状及分级中空结构的Cu S@MoS₂复合材料的CO₂起始还原₂)电位较低,具有潜在的电催化活性。更多还原

【Abstract】 Electrocatalysts for electrochemical reduction of CO₂ （CO₂ RR） have been mainly focused on noble metals or carbon nanomaterials,while the scarcity of noble metals and low selectivity of carbon materials are obvious drawbacks for their further applications.Therefore,researches regarding to high-quality and widely available electrocatalysts are strongly needed.Molybdenum disulfide （MoS₂） is a promising layered semiconductor material with a bandgap of 1.8 eV,which has insufficient active sites due to its easy agglomeration.The hybridization of copper sulfide （CuS） can change its electronic structure and enhance its catalytic performance.We report a facile morphology-tunable method to construct CuS-MoS₂ nanohybrids.Using Cu nanowire as template,CuS@MoS₂ heterostructures are prepared by a one-pot solvothermal process,in which the deposition of MoS₂ and transition of Cu to CuS occur simultaneously.More importantly,different morphologies of the composites including nanorod （NR）,hierarchical hollow and solid nanospheres （HHNS and SNS）,can be selectively fabricated simply by adjusting solvent proportion and precursor ratio.When the proportion of ethanol in the reaction system is lower,a rod-like morphology as highly ordered structure is developed.As the ethanol-water ratio increases,it takes a longer time for CuS to be deposited because of a decreased solvent polarity,Cu nanowire tends to bend itself into helical ring bundles,MoS₂ is deposited on its surface to form a multi-layered hierarchical hollow structure.As the dosage of Cu nanowire increases,the interspace of helical bundles shrinks so that the curved CuS@MoS₂ merges with each other to form a solid sphere.Preliminary results show that the CuS@MoS₂ NR and HHNS structures have relatively low CO₂ initial reduction potential and potential electrocatalytic activity.更多还原