Direct probing of atomically dispersed Ru species over multi-edged TiO ₂ for highly efficient photocatalytic hydrogen evolution

Abstract

A cocatalyst is necessary for boosting the electron-hole separation efficiency and accelerating the reaction kinetics of semiconductors. As a result, it is of critical importance to in situ track the structural evolution of the cocatalyst during the photocatalytic process, but it remains very challenging. Here, atomically dispersed Ru atoms are decorated over multi-edged TiO2 spheres for photocatalytic hydrogen evolution. Experimental results not only demonstrate that the photogenerated electrons can be effectively transferred to the isolated Ru atoms for hydrogen evolution but also imply that the TiO2 architecture with multi-edges might facilitate the charge separation and transport. The change in valence and the evolution of electronic structure of Ru sites are well probed during the photocatalytic process. Specifically, the optimized catalyst produces the hydrogen evolution rate of 7.2 mmol g−1 hour−1, which is much higher than that of Pt-based cocatalyst systems and among the highest reported values.

Visible‐Light Responsive TiO2‐Based Materials for Efficient Solar Energy Utilization

“…have synthesized atomically dispersed Ru atoms doped multiedged TiO 2 spheres (denoted as ME‐TiO 2 @Ru) for photocatalytic H 2 generation ( Figure 2 A). [ 53 ] Compared with the undoped one, the ME‐TiO 2 @Ru show photocatalytic activity under visible light even at the wavelength up to 450 nm (Figure 2B). The overall H 2 generation rate is estimated to 323.2 µmol h −1 , which is 34 times higher than that of undoped one (Figure 2C).…”

“…A–C) Adapted with permission. [ 53 ] Copyright 2020, Nature Publishing Group. D) Schematic illustration of molten‐salt‐mediated preparation of atomic Ni metals on TiO 2 .…”

“…C) Time-dependent hydrogen evolution over different catalysts. A-C) Adapted with permission [53]. Copyright 2020, Nature Publishing Group.…”

Atomically Dispersed Reactive Centers for Electrocatalytic CO2 Reduction and Water Splitting

“…[1][2][3][4][5] Among various types of energy conversion approaches,electrochemical CO 2 reduction and water splitting have been proven as promising strategies for their environmental benignancy and high efficiencies. [6][7][8][9][10] As demonstrated, the efficiency of the above-mentioned energy conversion approaches is highly related to the sluggish kinetics of the rate-determining step. [11][12][13][14] In this regard, developing durable and highly efficient electrocatalysts is of vital importance to accelerate the reaction kinetics and thus improve the overall energy conversion efficiency.…”

“…The development of renewable and efficient energy conversion technologies is a necessary requirement to meet the growing demand of energy consumption and environmental protection [1–5] . Among various types of energy conversion approaches, electrochemical CO 2 reduction and water splitting have been proven as promising strategies for their environmental benignancy and high efficiencies [6–10] . As demonstrated, the efficiency of the above‐mentioned energy conversion approaches is highly related to the sluggish kinetics of the rate‐determining step [11–14] .…”