Preparation of Nickel-based oxide photocatalytic Nano materials and their application in Hydrogen production

Abstract

This thesis investigates the synthesis and application of Ni₂O₃ nanoparticles in photocatalytic hydrogen generation, employing a novel microfluidic synthesis method based on a centrifugal microfluidic chip platform and a traditional participation method. The research demonstrates a significant reduction in chemical synthesis reaction time from 2 hours to just 5 minutes while enhancing the uniformity of nanoparticle size distribution, addressing common challenges in nanomaterial synthesis. The study focuses on the development of a TiO₂-Ni₂O₃/carbon nanotube (CNT) heterojunction composite that serves as an effective catalyst for hydrogen production. The synthesized composite achieved an impressive hydrogen generation rate of 1422 µmol/g/h, outperforming traditional TiO₂ catalysis by more than eleven times. Characterization techniques such as X-ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), X-ray Photoelectron Spectroscopy (XPS), UV-Visible spectroscopy, photocurrent measurements, photoluminescence (PL), and Electrochemical Impedance Spectroscopy (EIS) were employed to elucidate the composite's morphology, structure, and optical properties. These analyses revealed that the incorporation of Ni₂O₃ significantly improved light absorption and charge separation efficiency, critical factors for effective photocatalysis. A core-shell structure was formed through calcination at 800°C, comprising Ni as the outer shell, NiO as an intermediate layer, and Ni₂O₃ as the core. This unique architecture optimized electron transfer and enhanced carrier lifetime, with electron lifetime increasing from 1.44 ns to 2.18 ns after treatment. Consequently, photocatalytic performance markedly improved, achieving a hydrogen generation rate of 2626.7 µmol/g/h under optimal conditions. Moreover, the carbon footprint associated with hydrogen production was measured at 81.91 kg CO₂-equivalent per kg of H₂ produced, indicating environmental considerations in the process, with potential reductions through the use of renewable energy sources and recycling techniques. This work highlights a promising, cost-effective approach to photocatalytic hydrogen generation and provides valuable insights into optimizing catalysts for sustainable energy solutions. By advancing our understanding of Ni₂O₃'s role in photocatalytic systems, this research contributes to the broader field of renewable energy technologies, emphasizing the importance of efficient materials and processes in addressing the global energy cris.

Date of Award	15 Oct 2025
Original language	English
Awarding Institution	University of Nottingham
Supervisor	Yong Ren (Supervisor), Yong (Sean) Shi (Supervisor) & Yuying Yan (Supervisor)