Oxygen Vacancies Boosted by Laser Irradiation Enable NiCo Layered Double Hydroxide with a High Oxygen Reduction/Evolution Catalytic Activity in Zn–Air Batteries and Water Splitting
Jiayin Shang, Changhua Xu, Qiguan Wang, Sumin Wang, Jian Chen, Xinhai Wang
Abstract
Layered double hydroxide (LDH) provides a unique platform to design low-cost multifunctional catalysts owing to the special lamellar structure and excellent performance. Herein, by using nickel-cobalt LDH grown on the conductive nickel foam (NF) skeleton (NiCo LDH/NF), a three-dimensional structure featured with multilayer petals is constructed. Benefiting from the simple and feasible fixed-point laser irradiation, NiCo LDH/NF shows boosted oxygen vacancies, resulting in efficient catalytic activities, with an oxygen evolution reaction overpotential of only 253.31 mV at 10 mA cm–2 and a half-wave potential of 0.79 V vs RHE for oxygen reduction reaction. Attractively, rechargeable Zn–air batteries (ZABs) using the laser-irradiated NiCo LDH/Ni foam (L-NiCo LDH/NF) as the catalytic electrode display a high peak power value of 126.29 mW cm–2, surpassing that of commercially grouped Pt/C-IrO2 (88.43 mW cm–2). Moreover, the as-obtained L-NiCo LDH/NF also delivers enhanced catalytic activity in hydrogen evolution. Accordingly, the developed ZABs can drive the overall water splitting reaction using L-NiCo LDH/NF as the electrodes. Meanwhile, the key role of oxygen vacancy in the catalyst was verified by using the calculation based on density functional theory. Therefore, the simple method of laser irradiation is confirmed as a feasible way to boost oxygen vacancies in materials with enabled multifunctional electrocatalysis.