Monolayered Ru1/TiO2 nanosheet enables efficient visible-light-driven hydrogen evolution

• Published in: Applied catalysis. B, Environmental Environmental, 2020-08, Vol.271, p.118925, Article 118925
• Main Authors: Li, Junmeng, Yi, Ding, Zhan, Fei, Zhou, Bo, Gao, Denglei, Guo, Dayi, Liu, Shoujie, Wang, Xi, Yao, Jiannian
• Format: Article
• Language: English
• Subjects: Catalysts; Electromagnetic absorption; Energy levels; Evolution; Hydrogen; Hydrogen evolution; Hydrogen production; Monolayered nanosheet; Nanosheets; Oxygen vacancies; Ruthenium; Single heteroatom doping; Solar energy; Titanium dioxide; Visible-light-driven
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.118925

The single-atom ruthenium doped monolayered TiO2 nanosheets are successfully synthesized. The single-atom Ru1 introduces an impurity energy level, allowing light absorption up to 700 nm, and an oxygen vacancy around Ru1 tends to be a charge trapping site, promoting rapid photogenerated electron separation and transportation, facilitating photocatalytic hydrogen evolution reaction under visible light irradiation. [Display omitted] •The single-atom ruthenium doped monolayered TiO2 nanosheets (Ru1/TiNS) were successfully prepared.•The Ru1/TiNS introduced an impurity energy level which extended light absorption up to 700 nm.•The Ru1/TiNS generated oxygen vacancies which promoted photogenerated electron separation and transportation.•The DFT calculation revealed Ru1 atom was both thermodynamically and kinetically favorable for photocatalytic H2 production.•Ru1/TiNS enabled efficient H2 evolution of 4.81 mmol h-1 g-1 under visible light, comparable to 8.95 mmol h-1 g-1 under full light spectrum. Efficient visible-light-driven hydrogen evolution (VLD-HER) is the most desirable for utilizing solar energy, but it remains a significant challenge to fabricate advanced photocatalysts. Herein, we report on a single-atom ruthenium doped monolayered TiO2 nanosheet catalyst (Ru1/TiNS). Unlike pure TiO2 with no VLD-HER activity, Ru1/TiNS enables efficient H2 evolution with a mmol h−1 g−1 magnitude (4.81) under visible light, comparable to 8.95 mmol h−1 g−1 under full light spectrum. Various ex-/in-situ characterizations and theoretical calculations reveal that the single-atom Ru1 introduces an impurity energy level, allowing light absorption up to 700 nm, and an oxygen vacancy around Ru1 tends to be a charge trapping site, promoting rapid photogenerated electron separation and transportation. This study provides a promising catalyst-design strategy for high-efficiency hydrogen production using solar energy.