MXene-transition metal compound sulfide and phosphide hetero-nanostructures for photoelectrochemical water splitting

Solar-driven photoelectrochemical water splitting (SPWS) is considered a sustainable and clean strategy for hydrogen (H2) generation on a large scale. Semiconductors are prevalent as photoelectrodes and demonstrate competency in converting incident photons to free electrons. However, semiconductor-based SPWS suffers seriously from poor efficiency, low corrosion resistance, and high cost. MXenes are a large family of 2D materials possessing excellent electronic conductivity, high anisotropy of holes and electrons, and a hydrophilic surface. In addition, their large surface area with tunable functional terminations can alter the work function and carrier transport properties that offer a broad spectrum of electronic features and provide a possibility to fabricate MXene-based composites with improved photoelectrochemical efficiency. Rationally designed hetero-nanostructures with a tunable bandwidth are being explored to maximize the efficiency of solar to H2 (STH) energy conversion. Combining MXenes with transition metal sulfide/phosphide can lead to excellent visible light photocatalytic activity, better electronic carrier transport, and increased STH efficiency. These promising results promote the state-of-art of MXene-transition metal compound sulfide and phosphide hetero-nanostructures as potential candidates for photoelectrochemical water splitting and other solar energy applications.