Low‐Energy Hydrogen Ions Enable Efficient Room‐Temperature and Rapid Plasma Hydrogenation of TiO2 Nanorods for Enhanced Photoelectrochemical Activity. Issue 46 (3rd October 2022)

• Record Type: Journal Article
• Authors: Wang, Xiaodan; Mayrhofer, Leonhard; Keunecke, Martin; Estrade, Sonia; Lopez‐Conesa, Lluis; Moseler, Michael; Waag, Andreas; Schaefer, Lothar; Shi, Weidong; Meng, Xiangjian; Chu, Junhao; Fan, Zhiyong; Shen, Hao
• Is Part Of: Small. Volume 18:Issue 46(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-03
• Subjects: black titania -- low‐energy hydrogen ions -- multiple penetration pathways -- rapid plasma hydrogenation -- room‐temperature hydrogenation -- solar water splitting; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202204136
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Hydrogenation is a promising technique to prepare black TiO2 (H‐TiO2 ) for solar water splitting, however, there remain limitations such as severe preparation conditions and underexplored hydrogenation mechanisms to inefficient hydrogenation and poor photoelectrochemical (PEC) performance to be overcome for practical applications. Here, a room‐temperature and rapid plasma hydrogenation (RRPH) strategy that realizes low‐energy hydrogen ions of below 250 eV to fabricate H‐TiO2 nanorods with controllable disordered shell, outperforming incumbent hydrogenations, is reported. The mechanisms of efficient RRPH and enhanced PEC activity are experimentally and theoretically unraveled. It is discovered that low‐energy hydrogen ions with fast subsurface transport kinetics and shallow penetration depth features, enable them to directly penetrate TiO2 via unique multiple penetration pathways to form controllable disordered shell and suppress bulk defects, ultimately leading to improved PEC performance. Furthermore, the hydrogenation‐property experiments reveal that the enhanced PEC activity is mainly ascribed to increasing band bending and bulk defect suppression, compared to reported H‐TiO2, a superior photocurrent density of 2.55 mA cm −2 at 1.23 V RHE is achieved. These findings demonstrate a sustainable strategy which offers great promise of TiO2 and other oxides to achieve further‐improved material properties for broad practical applications. Abstract : A room‐temperature and rapid plasma hydrogenation (RRPH) strategy achieving low‐energy hydrogen ions to prepare H‐TiO2 nanorods with controllable disordered shell, exceeding state‐of‐the‐art hydrogenations, is developed. The mechanisms of RRPH and enhanced photoelectrochemical activity are revealed by experimental and theoretical means. This study offers a promising strategy to improve the properties of TiO2 and other oxides for variety of applications.