Controlled Growth of the Interface of CdWO_x/GDY for Hydrogen Energy Conversion

Abstract Directly extracting hydrogen energy from water in one device to achieve sustainable hydrogen energy generation‐conversion‐electricity storage system is an ideal major step forward for enabling a zero‐pollution, hydrogen‐fueled economy. The new concept of hydrogen energy conversion can be enabled by spontaneous reduction of nitrate to ammonia driven by potential differences between the well‐matched anode and cathode, leading to the full use of the electrochemical redox reactions to generate electric energy. The hydrogen energy in the acidic electrolyte can be transformed to electric energy with the rationally assembled primary battery, which can simultaneously power the electric devices and produce high value‐added ammonia. The new concept of hydrogen conversion device shows a record‐high specific capacity of 15 500 mA h g^–1 and achieves the highest ammonia production rate (149 mmol g_cat^–1 h^–1) and Faradaic Efficiency (99.2%) in acidic electrolytes. This work opens a new direction for hydrogen conversion and utilization which has obvious advantages over lithium and battery solutions.