Luo, et al (2024) A novel nano-cerium oxide functionalized biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More composite for degradation of organic dye: insight of the photocatalysis mechanism. Environmental Science and Pollution Research. https://doi.org/10.1007/s11356-024-32828-7

In recent years, the field of environmental remediation has witnessed a significant interest in visible-light-driven photocatalysis, particularly for the degradation of environmental organic pollutants. A groundbreaking study has introduced cerium-doped biochar, synthesized via a hydrothermal method, as a potent photocatalyst for the degradation of rhodamine B, a representative organic pollutant, under visible light. Remarkably, this novel photocatalyst achieved near-complete removal (almost 100%) of rhodamine B under visible light irradiation for 60 minutes at a pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More of 3, using a concentration of 2.0 g·L−1. This efficiency starkly contrasts with the modest removal rates of about 25.50% and 29.60% observed for cerium dioxide and biochar, respectively, under identical conditions.

The study meticulously demonstrates that the degradation process adheres to a pseudo-first-order kinetic model, with the cerium-doped biochar showing a photodegradation rate constant (0.0485·min−1) significantly surpassing those of biochar and cerium dioxide alone. This enhanced performance is attributed to the synergistic effects of hole (h+), superoxide (O2−∙), and hydroxyl (∙OH) radicals in the photocatalytic system, with a predominant role played by h+ and ∙OH radicals.

Further analysis reveals that the cerium-doped biochar not only serves as an excellent carrier for cerium dioxide, enhancing its photocatalytic activity, but also features a narrower band gap. This characteristic facilitates improved separation and migration of photogenerated electron–hole pairs under visible-light excitation, leading to the enhanced photodegradation of rhodamine B. The findings from this study not only offer valuable insights into the design of biochar-based photocatalysts but also underscore their potential application in tackling environmental organic pollution. Through this innovative approach, the study paves the way for more efficient and sustainable methods of environmental remediation.