A comparative overview of the recent progress of some novel metal oxide and sulfide nanomaterials-based photocatalyst

As a sustainable energy alternative, research into efficient photocatalysts is still ongoing. Photocatalytic materials are classified as elemental or compounds based on their composition. In addition, there are three categories of intrinsic semiconducting materials that exhibit notable photocatalytic efficiency: carbon-based, non-carbonbased, and metal-based materials. However, the sudden outrage in photocatalytic applications using metal-based semiconducting materials, especially oxide and sulfide compounds, happens due to the characteristic properties of these materials, which extend to their stability, extended bandgap, and light harvesting capacity. Further, the better electron transmission efficiency made these materials better for application relative to other similar semiconducting materials. Furthermore, a comparative analysis of the latest advancements in photocatalytic dye degradation with respect to the ef- ficiency, recyclability, and structural design of those nanomaterials will be described. Further, the mechanism behind photocatalytic dye degradation will be discussed based on the density of states (DOS), band structure, and optical properties of the crystals via density functional theory (DFT). Finally, a clear road map will be given from the perspective of future improvement.