Self‐Co‐Electrolysis for Co‐Production of Phosphate and Hydrogen in Neutral Phosphate Buffer Electrolyte
Heng Xu, Guanxing Xu, Lisong Chen, Jianlin Shi
Abstract
Abstract The spontaneous reaction between Zn and H 2 O is of critical importance and could plausibly be used to produce H 2 gas, especially under neutral conditions. However, this reaction has long been overlooked owing to its sluggish kinetics and Zn consumption. Herein, a unique self‐co‐electrolysis system (SCES) is reported, which uses a Zn anode, a CoP‐based catalytic cathode, and a neutral phosphate buffer solution (PBS) as the electrolyte. In this SCES, Zn is not only a sacrificial anode but also an important precursor of high‐value‐added NaZnPO 4 . Additionally, the composition and phase structure of NaZnPO 4 can be well regulated. In this study, a high‐performance N,Cu‐CoP/carbon cloth (CC) catalyst is synthesized to catalyze the cathodic hydrogen evolution reaction (HER) at an especially low overpotential of 64.7 mV at 10 mA cm − 2 . H 2 gas (13.7 mL cm − 2 h − 1 ) and NaZnPO 4 (3.73 mg cm − 2 h − 1 ) are obtained at the cathode and anode, respectively, in the N,Cu‐CoP/CC||Zn SCES spontaneously. Moreover, the SCES has a favorable open‐circuit voltage (OCV) of 0.79 V and a maximum power density of 1.83 mW cm − 2 . Density functional theory (DFT) calculations are performed to elucidate the electronic structure and HER catalytic mechanism of the N and Cu co‐doped CoP catalysts.