Gupta Smita, Gandhi Jemi, Kokate Santosh, Raikar Laxman G, Kopuri Vijayakumar Gupta, Prakash Halan
Energy and Environmental Chemistry Laboratory, Department of Chemistry, Birla Institute of Technology and Science, Pilani, K K Birla Goa Campus, NH17B, Zuarinagar, Goa, 403726, India.
Aditya Birla Science & Technology Co. Pvt. Ltd., Taloja, Mumbai, 410208, India.
Heliyon. 2023 May 19;9(5):e16450. doi: 10.1016/j.heliyon.2023.e16450. eCollection 2023 May.
Photocatalytic degradation of organic pollutants in water using graphitic carbon nitride and persulfate under visible light (g-CN/PS system) has been studied. Here, we demonstrate augmentation of photocatalytic degradation of Acetaminophen (AAP) using hydrothermally treated g-CN and PS under 400 nm LED irradiation (HT-g-CN/PS system). A pseudo-first-order rate constant (k 0.328 min) for degradation of AAP using HT-g-CN/PS system was determined to be 15 times higher compared to g-CN/PS system (k 0.022 min). HT-g-CN showed a higher surface area (81 m/g) than g-CN (21 m/g). Photocurrent response for HT-g-CN was higher (1.5 times) than g-CN. Moreover, Nyquist plot semicircle for HT-g-CN was smaller compared to g-CN. These results confirm effective photoelectron-hole separation and charge-transfer in HT-g-CN compared to g-CN. AAP degradation using HT-g-CN/PS system was significantly inhibited with and h scavengers compared to O and scavengers. ESR results revealed formation in HT-g-CN/PS system. Moreover, photocurrent measurements reveal AAP oxidation by h of HT-g-CN was effective than g-CN. HT-g-CN was reused for five cycles in HT-g-CN/PS system. Augmented photocatalytic degradation of AAP by HT-g-CN/PS system compared to g-CN/PS is attributed to effective photoelectron hole separation of HT-g-CN that generates and h for oxidation of pollutant. Importantly, electrical energy per order (E) was 7.2 kWh m order. k for degradation of AAP in simulated groundwater and tap water were determined as 0.029 and 0.035 min, respectively. Degradation intermediates of AAP were proposed. AAP ecotoxicity against marine bacteria was completely removed after treatment by HT-g-CN/PS system.
研究了在可见光下使用石墨相氮化碳和过硫酸盐对水中有机污染物进行光催化降解（g-CN/PS体系）。在此，我们展示了在400nm LED照射下，使用水热法处理的g-CN和PS增强对乙酰氨基酚（AAP）的光催化降解（HT-g-CN/PS体系）。使用HT-g-CN/PS体系降解AAP的准一级速率常数（k = 0.328 min⁻¹）被确定为比g-CN/PS体系（k = 0.022 min⁻¹）高15倍。HT-g-CN的比表面积（81 m²/g）高于g-CN（21 m²/g）。HT-g-CN的光电流响应比g-CN高（1.5倍）。此外，HT-g-CN的奈奎斯特图半圆比g-CN小。这些结果证实与g-CN相比，HT-g-CN中光生电子-空穴分离和电荷转移更有效。与O₂⁻和·OH清除剂相比，使用HT-g-CN/PS体系降解AAP时，·O₂⁻和h⁺清除剂对其有显著抑制作用。电子顺磁共振（ESR）结果显示HT-g-CN/PS体系中生成了·O₂⁻。此外，光电流测量结果表明HT-g-CN的h⁺对AAP的氧化比g-CN更有效。HT-g-CN在HT-g-CN/PS体系中可重复使用五个循环。与g-CN/PS体系相比，HT-g-CN/PS体系对AAP的光催化降解增强归因于HT-g-CN有效的光生电子-空穴分离，其产生·O₂⁻和h⁺用于氧化污染物。重要的是，每降解一个数量级的电能（E）为7.2 kWh m⁻³ order⁻¹。在模拟地下水和自来水中降解AAP的k值分别确定为0.029和0.035 min⁻¹。提出了AAP的降解中间体。经HT-g-CN/PS体系处理后，AAP对海洋细菌的生态毒性被完全去除。
