# Photoinduced loading of electron-rich Cu single atoms by moderate coordination for hydrogen evolution

## TL;DR

Researchers developed a method to create highly stable copper single-atom catalysts using light and hydrogen, which improves hydrogen production efficiency.

## Contribution

A photochemical strategy enables high-loading, electron-rich Cu single atoms on black phosphorus for efficient hydrogen evolution.

## Key findings

- The catalyst achieved a low overpotential of 41 mV at 10 mA cm−2 for hydrogen evolution.
- The Cu-P3 structure showed a Tafel slope of 53.4 mV dec−1, outperforming Cu nanoclusters and isolated atoms.
- Neighboring Cu atoms synergistically lower the energy of water dissociation intermediates.

## Abstract

Single-atom catalysts offer maximal atom utilization efficiencies and high-electronegativity heteroatoms play a crucial role in coordinating reactive single metal atoms to prevent agglomeration. However, these strong coordination bonds withdraw electron density for coordinated metal atoms and consequently affect their catalytic activity. Herein we reveal the high loading (11.3 wt%) and stabilization of moderately coordinated Cu-P3 structure on black phosphorus support by a photochemical strategy with auxiliary hydrogen. Single-atom Cu sites with an exceptional electron-rich feature show the \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$\triangle {G}_{{{{{{\rm{H}}}}}}*}$$\end{document}△GH* close to zero to favor catalysis. Neighboring Cu atoms work in synergy to lower the energy of key water adsorption and dissociation intermediates. The reported catalyst shows a low overpotential of only 41 mV at 10 mA cm−2 and Tafel slope of 53.4 mV dec−1 for the alkaline hydrogen evolution reaction, surpassing both isolated Cu single atoms and Cu nanoclusters. The promising materials design strategy sheds light on the design and fabrication of high-loading single metal atoms and the role of neighboring single atoms for enhanced reaction kinetics.

While atomically dispersed metals can maximize reaction catalytic sites, it is challenging to achieve high atomic densities without agglomeration. Here, authors prepared Cu single-atoms on black phosphorous using a photochemical strategy and auxiliary H2 as proton reduction electrocatalysts.