Study of CuO/TiO2/Polyindole (CTPIN) electrocatalyst in membraneless electrolyzer for solar hydrogen generation

Abstract

Efficient electrocatalysts are indispensable for promoting the hydrogen evolution reaction (HER). Existing electrocatalysts are limited by sluggish HER kinetics, higher over potential leading to greater energy demand, instability over time, and low tolerance to impurities. These challenges lead to a lower solar-to-hydrogen conversion efficiency of 2.46% using MoS2 electrocatalyst in authors’ previous research work. Mixed metal oxide/conducting polymer nanocomposites have shown great potential for use in hydrogen evolution reaction (HER) reactors due to their high surface area, excellent catalytic activity, and stability in acidic and alkaline environments. A major requirement for suitable electrocatalyst is a low overpotential for hydrogen evolution, a high tolerance to impurities and a long-term durability which makes it more efficient than traditional electrocatalysts. With this brief background, the present work focuses on the application of CuO/TiO2/Polyindole (CTPIN) nanocomposite synthesized with the help of two-step process involving microemulsion and oxidative polymerization techniques. The resulting material was characterized using miscellaneous physicochemical techniques. HRTEM analysis clearly demonstrates the formation of CTPIN nanocatalysts with ultrasmall particle sizes of 10–30 nm. The nickel strip was coated with CTPIN nanoparticles was used as cathode for generating solar hydrogen through membraneless electrochemical water splitting. Membraneless electrolyzers offer a promising and cost-effective substitute to traditional electrolyzers, enabling efficient electrochemical hydrogen generation. At a radiation intensity of 320 W/m2 and under normal working conditions, the CTPIN nanocomposite demonstrated a solar-to-hydrogen generation efficiency of 3.43% which is greater than previous results obtained using MoS2. The CTPIN electrocatalyst has a high potential for electrocatalytic solar hydrogen generation. The CTPIN electrocatalyst could make it possible to produce hydrogen from clean and renewable energy source.