Polysaccharide-templated bismuth phosphate: Structural and optical engineering for superior photocatalytic applications

초록

Development of green, straightforward, and efficient strategies for advanced materials synthesis has gained significant attention in recent years. Herein, a facile precipitation route was employed to synthesize bismuth phosphate (BiPO4), using chitosan (Cs) and sodium alginate (Alg) as biopolymeric templates. Photocatalytic activity of the synthesized materials was assessed toward methylene blue (MB) degradation under UV-C irradiation. To the best of our knowledge, the use of Cs and Alg as templating agents in BiPO(4)synthesis has not been previously reported. Structural analysis confirmed monoclinic scheelite-type BiPO(4)with rod-like morphology. UV-Vis DRS measurements revealed a significant reduction in the band gap energy from 4.64 eV (BiPO4) to 3.90 eV (BiPO4-Cs), indicating enhanced light-harvesting capability. Moreover, the incorporation of Cs and Alg contributed to particle size reduction and surface charge modification, as confirmed by the point of zero charge (pHpzc) measurements. Among all synthesized samples, BiPO4-Cs exhibited the highest specific surface area (SSA: 7.35 m(2)/g), which contributed to its superior photocatalytic degradation efficiency towards MB. The degradation pathway was elucidated using liquid chromatography-mass spectrometry (LC-MS) analysis. Additionally, BiPO4-Cs demonstrated remarkable stability and reusability, maintaining its photocatalytic performance over five consecutive degradation cycles.

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