原子层沉积制备钴镍硫化物薄膜的方法学研究及其在电催化方面的应用

Cobalt nickel sulfides are an important hot-spot materials category for electrocatalysis, but it is still unknown which phase and stoichiometry of cobalt nickel sulfides is the best for electrocatalysis. Atomic layer deposition (ALD) technology has been widely regarded as a highly-promising, novel, and highly-controllable thin film deposition technology, as it can realize the precise control of film composition and thickness, and it can also be employed to uniformly coat complex porous structures. In this project, we will use ALD to systematically fabricate cobalt nickel sulfide films with various phases and compositions, and investigate and optimize the effect of phase and composition for their electrocatalytic performance. Since there is no currently existing ALD processes reported for cobalt nickel sulfides, the most important goal is to study and develop an ALD process for a series of cobalt nickel sulfides with high controllability. Therefore, we would like to first design and synthesize the precursors for cobalt and nickel, and then carefully develop the ALD process and study the surface chemistry reaction mechanisms by in-situ methods in the associated ALD process. These studies would help us to achieve the high controllability and adjustability for the ALD process. Finally, we will coat the optimized ALD cobalt nickel sulfide films uniformly on electrode frameworks with high surface areas, and thus the total electrocatalytic performance will be maximized. This study is not only meaningful from the fundamental ALD methodology point of view, but the idea of separately optimizing the geometry for the frameworks and the materials on the surface can also be widely applied to various other similar situations.

硫化钴镍是一类重要的热点电催化材料，但目前并不清楚哪种晶相组成的硫化钴镍比性能最好。原子层沉积（ALD）技术是一种受到广泛看好的新型可控薄膜制备技术，它能够对薄膜的成分实现精确可控，并可将薄膜均匀包覆在复杂多孔结构上。本项目将利用ALD技术来系统地制备各种晶相组成的硫化钴镍薄膜，深入研究晶相组成对其电催化性能的影响并进行优化。因目前尚未有硫化钴镍的ALD方法报道，所以本项目的重点是研发一系列硫化钴镍的ALD可控制备方法。为此我们拟从前驱体的设计与合成开始，研发ALD工艺，并通过原位在线手段，深入探究ALD过程中的表面化学反应机理，实现对硫化钴镍制备方法的高度可控与可调性。最后，我们将优化后的ALD硫化钴镍薄膜均匀包覆在高表面积电极骨架结构上，从整体上提高电极的电催化性能。本研究不仅在ALD的基础方法学研究方面有重要的意义，而且这种分立优化骨架几何结构与表面性能的思路具有广泛的应用借鉴意义。

以钴镍硫化物为代表的过渡金属硫化物是一类重要的电催化材料。原子层沉积（ALD）技术作为一种新兴的薄膜材料制备技术，所得薄膜具有原子尺度可操控性，非常适合应用于催化等性能主要取决于材料表面性质的应用领域。本项目主要围绕原子层沉积在电催化方面的应用，开展了原子层沉积制备过渡金属硫化物薄膜的方法学研究。项目重点研发了一系列镍、钴、铁硫化物材料的新型原子层沉积制备方法，并通过原位X射线光电子能谱、原位石英晶振微天平技术和在线质谱等手段，深入研究了原子层沉积过程中的机理机制问题，包括反应-团聚机制、前驱体热裂解过程等，对原子层沉积新方法开发具有重要的指导意义。项目进一步将所制得的原子层沉积材料应用于电解水析氢、电解水析氧和氧还原等多个电催化反应，取得了良好的效果，体现了原子层沉积技术在电催化领域的良好应用前景。