Da Yumin, Tian Zhangliu, Jiang Rui, Chen Ganwen, Liu Yuan, Xiao Yukun, Zhang Jinfeng, Xi Shibo, Chen Wei, Han Xiaopeng, Hu Wenbin
Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China.
Department of Chemistry, National University of Singapore, Singapore 117551, Singapore.
ACS Nano. 2023 Sep 26;17(18):18539-18547. doi: 10.1021/acsnano.3c06595. Epub 2023 Sep 7.
Exploring highly efficient single atom catalysts with defined active centers and tunable electronic structures is highly desirable. Herein, we developed an efficient hydrogen evolution reaction (HER) electrocatalyst through a self-gating phenomenon induced by Pt single atoms (SAs) supported on ultrathin NiO nanosheets (Pt-NiO). The Ni atoms in NiO are partially replaced by the atomically dispersed Pt atoms, leading to a transition from p-type NiO into n-type Pt-NiO. When the n-type Pt-NiO serves as HER electrocatalyst, the self-gating phenomenon occurs in the ultrathin nanosheets, resulting in a mixture of leakage ("active") and metal-insulator-semiconductor ("inert") regions. The "inert" region induced by the ionic gating and reverse potential is capable of accumulating relatively high surface charge carrier concentration with an ultrahigh electric field, making the Pt-NiO highly conductive; meanwhile, the HER process occurs at the Pt SAs sites (active region) in the Pt-NiO nanosheets. As a result, the Pt-NiO requires only 55 mV to deliver 10 mA/cm in an alkaline solution with good stability.
探索具有明确活性中心和可调电子结构的高效单原子催化剂是非常必要的。在此，我们通过负载在超薄氧化镍纳米片（Pt-NiO）上的铂单原子（SAs）诱导的自门控现象，开发了一种高效的析氢反应（HER）电催化剂。氧化镍中的镍原子被原子分散的铂原子部分取代，导致从p型氧化镍转变为n型Pt-NiO。当n型Pt-NiO用作HER电催化剂时，超薄纳米片中会出现自门控现象，导致泄漏（“活性”）区域和金属-绝缘体-半导体（“惰性”）区域的混合。由离子门控和反向电位诱导的“惰性”区域能够在超高电场下积累相对较高的表面电荷载流子浓度，使Pt-NiO具有高导电性；同时，HER过程发生在Pt-NiO纳米片中的Pt SAs位点（活性区域）。因此，Pt-NiO在碱性溶液中仅需55 mV即可达到10 mA/cm²，且具有良好的稳定性。
