Ranjan Rahul, Bhatt Smruti B, Rai Rohit, Sharma Sanju Kumari, Ranjan Rishabh, Bharti Ankit, Dhar Prodyut
School of Biochemical Engineering, Indian Institute of Technology (BHU) Varanasi Uttar Pradesh-221005 India
Department of Biotechnology, National Institute of Technology Durgapur West Bengal 713209 India.
RSC Adv. 2024 Apr 16;14(17):12192-12203. doi: 10.1039/d4ra00862f. eCollection 2024 Apr 10.
Rice husk (RH) is a common agricultural waste generated during the rice milling process; however, a major portion is either burned or disposed of in landfills, posing significant environmental risks. In this study, RH waste was transformed into bio-based catalysts delignification cum growth of MoS (DRH-MoS) for efficient pollutant dye removal and microbial decontamination. The developed DRH-MoS exhibits nanoflower-like structures with a 2H-MoS phase and a narrow band gap of 1.37 eV, which showed strong evidence of photocatalytic activity. With the presence of abundant hydroxyl functionality, delignified rice husk (DRH) exhibits a malachite green (MG) dye adsorption capacity of 88 mg g. However, growth of MoS nanosheets on DRH enhances MG degradation to 181 mg g under dark conditions and 550 mg g in the presence of light. Mechanistic insights reveal a synergistic adsorption--degradation phenomenon, amplified by generation of reactive oxygen species during photodegradation which was confirmed from radical scavenging activity. Interestingly, DRH-MoS demonstrates potent antibacterial activity against () and () with sustained photodegradation efficiency (>80%) over three cycles. The present work reports a cost-effective and scalable strategy for environmental remediation of real wastewater which usually contains both dye pollutants as well as microbes using abundantly available renewable resources such as sunlight and agricultural biomass wastes.
稻壳（RH）是稻米加工过程中产生的一种常见农业废弃物；然而，大部分稻壳要么被焚烧，要么被丢弃在垃圾填埋场，带来了重大的环境风险。在本研究中，稻壳废弃物被转化为用于高效去除污染物染料和进行微生物净化的生物基催化剂——脱木质素并生长有二硫化钼的稻壳（DRH-MoS）。所制备的DRH-MoS呈现出类似纳米花的结构，具有2H-MoS相和1.37 eV的窄带隙，这显示出其具有光催化活性的有力证据。由于存在丰富的羟基官能团，脱木质素稻壳（DRH）对孔雀石绿（MG）染料的吸附容量为88 mg/g。然而，在DRH上生长的二硫化钼纳米片在黑暗条件下可将MG降解率提高到181 mg/g，在光照条件下则提高到550 mg/g。机理研究揭示了一种协同吸附——降解现象，光降解过程中活性氧的产生放大了这种现象，这一点通过自由基清除活性得到了证实。有趣的是，DRH-MoS对大肠杆菌（E. coli）和金黄色葡萄球菌（S. aureus）表现出强大的抗菌活性，在三个循环中光降解效率持续保持在80%以上。本研究报道了一种具有成本效益且可扩展的策略，用于利用阳光和农业生物质废弃物等丰富的可再生资源对通常同时含有染料污染物和微生物的实际废水进行环境修复。
