Zhuang Linzhou, Xu Fang, Wang Keyu, Li Jianku, Liang Chen, Zhou Wei, Xu Zhi, Shao Zongping, Zhu Zhonghua
School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 211800, China.
Small. 2021 May;17(20):e2100121. doi: 10.1002/smll.202100121. Epub 2021 Apr 1.
Water electrolysis, which is a promising high-purity H production method, lacks pH-universality; moreover, highly efficient electrocatalysts that accelerate the sluggish anodic oxygen evolution reaction (OER) are scarce. Geometric structure engineering and electronic structure modulation can be efficiently used to improve catalyst activity. Herein, a facile Ar plasma treatment method to fabricate a composite of uniformly dispersed iridium-copper oxide nanoclusters supported on defective graphene (DG) to form IrCuO @DG, is described. Acid leaching can be used to remove Cu atoms and generate porous IrO nanoclusters supported on DG (P-IrO @DG), which can serve as efficient and robust pH-universal OER electrocatalysts. Moreover, when paired with commercial 20 wt% Pt/C, P-IrO @DG can deliver current densities of 350.0, 317.6, and 47.1 mA cm at a cell voltage of 2.2 V for overall water splitting in 0.5 m sulfuric acid, 1.0 m potassium hydroxide, and 1.0 m phosphate buffer solution, respectively, outperforming commercial IrO and nonporous IrO nanoclusters supported on DG (O-IrO @DG). Probing experiment, X-ray absorption spectroscopy, and theoretical calculation results demonstrate that Cu removal can successfully create P-IrO nanoclusters and introduce unsaturated Ir atoms. The optimum binding energies of oxygenated intermediate species on unsaturated Ir sites and ultrafine IrO nanoclusters contribute to the high intrinsic OER catalytic activity of P-IrO @DG.
水电解是一种很有前景的高纯度制氢方法，但缺乏pH通用性；此外，能加速缓慢的阳极析氧反应（OER）的高效电催化剂也很稀缺。几何结构工程和电子结构调制可有效用于提高催化剂活性。在此，描述了一种简便的氩等离子体处理方法，用于制备负载在缺陷石墨烯（DG）上的均匀分散的铱 - 铜氧化物纳米团簇的复合材料，以形成IrCuO@DG。酸浸可用于去除铜原子，并生成负载在DG上的多孔IrO纳米团簇（P - IrO@DG），其可作为高效且耐用的pH通用OER电催化剂。此外，当与商业20 wt% Pt/C配对时，P - IrO@DG在0.5 m硫酸、1.0 m氢氧化钾和1.0 m磷酸盐缓冲溶液中进行全水解时，在2.2 V的电池电压下分别可提供350.0、317.6和47.1 mA cm的电流密度，性能优于商业IrO和负载在DG上的无孔IrO纳米团簇（O - IrO@DG）。探测实验、X射线吸收光谱和理论计算结果表明，去除铜可以成功创建P - IrO纳米团簇并引入不饱和铱原子。不饱和铱位点上含氧中间物种的最佳结合能和超细IrO纳米团簇有助于P - IrO@DG具有高本征OER催化活性。
