表面结构调整混合度硫化铜在水电解过程中的电化学行为
Avinava Kundu1, Biswarup Chakraborty1
1Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
JACS Au
|March 1, 2024
概括
混合价值铜硫化物,二基尼特Cu9S5和合体CuS,由于表面的铜部位,表现出不同的电化学行为. 在现场形成的氧化铜与原始硫化物相比,具有优越的电催化水分性能.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 纳米技术纳米技术
背景情况:
- 混合价值的硫化铜 (Cu9S5和CuS) 具有与Cu-S共价和交换合相关的半导体特性.
- 之前对Cu9S5和CuS的电催化研究缺乏与格子结构相关的详细的氧化还原化学解释.
研究的目的:
- 研究纳米结构Cu9S5和CuS作为电极材料的详细氧化还原化学.
- 为了将电化学反应与格子结构,表面原子排列和协调几何学相关联.
- 了解硫化铜的 in situ 转化及其用于水分的电催化活性.
主要方法:
- 制备纳米结构的Cu9S5和CuS.
- 电化学研究使用循环电压测量和时电压测量.
- 通过粉末X射线衍射 (PXRD),显微镜,X射线光电子光谱 (XPS),拉曼光谱,接触角和BET分析进行结构和表面表征.
主要成果:
- Cu9S5表现出具有多种Cu位点 (Td CuII,O CuII,Tp CuI) 的d(0015) 表面,而CuS只有Td CuII.的d(002) 表面.
- Cu9S5在电化学上更不稳定,迅速转化为CuO/Cu2O,其高表面能量,宏孔结构增强了电解质扩散.
- 在现场形成的铜氧化物 (CuO/Cu2O/Cu(OH) 2) 与原始铜硫化物相比,具有优越的电催化水分性能.
结论:
- Cu9S5和CuS之间的电化学差异主要是由于不同的表面铜位和氧化还原状态.
- 潜在驱动的结构转变导致高活性氧化铜电催化剂的形成.
- 结构-活性相关性为解释硫化金属电化学及其催化转化途径提供了洞察力.
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