LaCoO3 photocatalyst for environmental remediation and energy conversion applications

Water quality and sanitation (Goal 6) and clean energy (Goal 7) have been some of the main focus under United Nations Sustainable Development Goals (UN-SDGs) which is closely intertwined with other goals such as poverty, health, sustainable cities and communities. Advanced efforts are being made to develop materials a method to explore innovative methods and materials stocks to fulfil the SDGs for future. Lanthanum Cobaltite (LaCoO3) perovskite oxide photocatalyst has garnered significant interest in various applications, including the remediation of organic pollutants through degradation in water treatment, hydrogen (H2) production, and Carbon dioxide (CO2) reduction. This review work offers a critical overview and detailed discussion of LaCoO3 based perovskite oxide photocatalyst systems that operate in the visible light range (λ > 400 nm). Moreover, it explores the mechanisms involved in the degradation of organic contaminants, hydrogen production, and CO2 reduction, providing interpretations for their formation and the steps involved in these processes. Although LaCoO3 based photocatalysts have demonstrated substantial potential for practical applications, challenges such as low charge transfer mobility, high electron-hole recombination rates, and the positions of the Valence Band Maximum (VBM) and Conduction Band Minimum (CBM) present significant barriers to large-scale implementation. This review critically evaluates various preparation routes for LaCoO3, emphasizing the importance of synthesis methods in optimizing photocatalytic performance. It also discusses the effects of transition metal doping, the formation of heterojunctions with LaCoO3 using other semiconductors, and the role of LaCoO3 as a co-catalyst in visible-light-driven photocatalysis. Furthermore, it addresses challenges related to hydrogen production, the degradation of organic pollutants, and selectivity issues in photocatalytic CO2 reduction.