Robust Ru-VO 2 Bifunctional Catalysts for All-Ph Overall Water Splitting.

Designing robust bifunctional catalysts for oxygen evolution and hydrogen evolution reactions (OER/HER) in all-pH conditions for overall water splitting (OWS) is an effective way to achieve sustainable development. Herein, we synthesize a composite Ru-VO 2 containing Ru-doped VO 2 and Ru nanoparticles (NPs), and it shows a high OWS performance in full-pH range due to their synergist effect. In particular, the OER mass activities of Ru-VO 2 at 1.53V (vs RHE) in acidic, alkaline and PBS solutions are approximately 65, 36 and 235 times of commercial RuO 2 in the same conditions. The "Ru-VO 2 || Ru-VO 2 " two-electrode electrolyzer only needs a voltage of 1.515 V (at 10 mA cm -2 ) in acidic water splitting, which can operate stably for 125 h at 10 mA cm -2 without significant voltage decay. In situ Raman spectra and in situ differential electrochemical mass spectrometry prove that the OER of Ru-VO 2 in acid follows the adsorption evolution mechanism. DFT calculations further revealed the synergistic effect between Ru NP and Ru-doped VO 2 , which breaks the hydrogen bond network formed by *OH adsorbed on the Ru single-atom site, and thereby significantly enhances the OER activity. This work provides new insights into the design of novel bifunctional pH-universal catalysts for OWS. This article is protected by copyright. All rights reserved.