High specific surface CeO₂–NPs doped loose porous C₃N₄ for enhanced photocatalytic oxidation ability

Abstract

Porous C3N4 (PCN) is favored by researchers because it has more surface active sites, higher specific surface area and stronger light absorption ability than traditional g-C3N4. In this study, cerium dioxide nanoparticles (CeO2-NPs) with mixed valence state of Ce3+ and Ce4+ were doped into the PCN framework by a two-step method. The results indicate that CeO2-NPs are highly dispersed in the PCN framework, which leads to a narrower band gap, a wider range of the light response and an improved the separation efficiency of photogenerated charge in PCN. Moreover, the specific surface area (145.69 m2•g-1) of CeO2-NPs doped PCN is a 25.5 % enhancement than that of PCN (116.13 m2•g-1). In the experiment of photocatalytic selective oxidation of benzyl alcohol, CeO2-NPs doped porous C3N4 exhibits excellent photocatalytic activity, especially Ce-PCN-30. The conversion rate of benzyl alcohol reaches 74.9 % using Ce-PCN-30 as photocatalyst by 8 hours of illumination, which is 25.7 % higher than that of pure porous C3N4. Additionally, CeO2-NPs doped porous C3N4 also exhibits better photocatalytic efficiency for other aromatic alcohols.

Flower-like Ag2WO4/CeO2 heterojunctions with oxygen vacancies and expedited charge carrier separation boost the photocatalytic degradation of dyes and drugs

“…4 However, CeO 2 with a band gap of 3.0 eV only responds to near ultraviolet light, and it is difficult to separate the photogenerated carriers, which limits the efficient conversion of solar energy. 5 A variety of strategies (e.g., defect modification, 6 regulating morphology, 7,8 and constructing heterojunctions [9][10][11] have been adopted to improve the visible light catalytic efficiency of CeO 2 . However, a single optimization strategy is usually adopted, limiting performance improvement.…”

“…5 A variety of strategies ( e.g. , defect modification, 6 regulating morphology, 7,8 and constructing heterojunctions 9–11 ) have been adopted to improve the visible light catalytic efficiency of CeO 2 . However, a single optimization strategy is usually adopted, limiting performance improvement.…”