A platinum modulated tungsten oxide on Ag nanowires network as an indicator for in-situ visualized evaluation of the hydrogen evolution performance

Abstract

The development of the real-time evaluation for the catalytic hydrogen evolution performance under a simple and convinient condiction is urgently needed, but still a great challenge. Herein, a platinum modulated WOx on Ag nanowires (Pt-WOx@Ag NWs) is developed as an optical-electrochemical catalyst to realize an in-situ intuitive evaluation for the hydrogen evolution performance, in which the color of as-prepared Pt-WOx@Ag NWs catalyst changes from the transparent to the deep blue with the increase of the applied potential. The real-time H2 evolution with an H2 turnover frequency (from 0 to 2.26 s−1 per site), optical transmittance (from 80.3% to 48.7% at the wavelength of 630 nm) and energy consumption (from 0 to 0.74 W h in 1 h) is established. The charge transfer and mass transport are greatly promoted by the three demensional Ag NWs conductive network and abundant active sites, which are provided by the platinum modulated WO3 on the Ag substrate. Density functional theory (DFT) calculations indicate that the modified WOx shows the preferred adsorption affinity toward H2O (ΔGH2O, −0.17 eV), which reach a high coloration efficiency and optical modulation range for the electrochromic reaction. The Pt sites on WOx with a suitable H binding energy (ΔGH∗, 0.38 eV) efficiently promote the H∗ conversion and H2 release of water splitting. This work propose an intelligent hydrogen evolution indicator by real-time color change to boost the high-quality development of green hydrogen energy.