Ni-based water photocatalysts for hydrogen evolution, and physical mechanism behind photocatalysis

This doctoral thesis is dedicated to the exploration and enhancement of Ni-based water photocatalysts, with a focus on their potential for efficient hydrogen evolution and unraveling the underlying physical mechanisms governing photocatalysis. The primary focus is on the utilization of commercial Ni@NiO/NiCO3 with varied sizes, subjected to vacuum annealing thermal treatment to enhance their photocatalytic properties. Additionally, the incorporation of Ag as a buffer element, facilitates the attachment of Ni to multilayered MoS2, resulting in the formation of a MoS2-Ag-Ni ternary composite. Furthermore, the synthesis of hierarchical Nickel carbonate hydroxide via the hydrothermal method is investigated. A comprehensive characterization of the synthesized materials is carried out using various microscopic techniques (SEM, TEM, HRTEM, etc.) and spectroscopic tools (UV-vis, XPS, XRD, EDS, etc.) to provide detailed insights into the structural and chemical composition of the materials. The synthesized materials are then subjected to photocatalytic water splitting experiments, wherein hydrogen production under visible light irradiation is investigated. The outcomes of this research not only contribute to the advancement of Ni-based photocatalysts but also enhance our understanding of the complicated interplay between material structures and their photocatalytic performance.