MXene introduced between CoNi LDH and NiMoO4 nanorods arrays: A bifunctional multistage composite for OER catalyst and supercapacitors

Abstract

To improve the electrochemical activity and electrochemical energy storage performance of the catalyst, one of the best approaches is to adjust materials structure reasonably and design of micro-array to enhance specific surface area and expose more active sites. In this work, CoNi-LDH/MXene@NiMoO4 electrode with multistage structure was successfully designed, in which CoNi-LDH was vertically arranged on NiMoO4 nanorods coated with MXene. Oxygen evolution reaction (OER) performance was improved through the adjustment of LDH by MXene. The electrode has an excellent OER activity, which the overpotential is 222 mV at 100 mA cm−2. In addition, it can maintain high efficiency and stable operation for 120 h. The overall water-splitting (OWS) electrolytic cell was assembled with CoNi-LDH/MXene@NiMoO4 electrodes, which exhibited a low cell voltage (1.56 V) at 10 mA cm−2. Moreover, the assembled OWS electrolytic cell can operate stably under the low voltage by small-scale solar power generation and thermal power generation. Furthermore, CoNi-LDH/MXene@NiMoO4 electrode also showed good potential in electrochemical energy storage. This work opened a new avenue for MXene to regulate the activity of transition metal-based catalysts. The efficient preparation of clean energy by the interaction of MXene and transition metal groups show great prospects.