Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Florida Science Campus, 1710, South Africa.
Sci Total Environ. 2022 Jul 10;829:154648. doi: 10.1016/j.scitotenv.2022.154648. Epub 2022 Mar 16.
Biochar (BC)-photocatalyst nanocomposites have emerged as appealing water and wastewater treatment technology. Such nanocomposite materials benefit from the synergistic effect of adsorption and photocatalysis to attain improved removal of pollutants from water and wastewater. Under this review, three BC-based nanocomposite photocatalysts such as BC-TiO, BC-ZnO, and BC-spinel ferrites were considered. These nanocomposites acquire intrinsic properties to improve the practical limitations of the pristine BC and photocatalysts. The BC-based nanocomposites attained high photocatalytic activity, mechanical hardness, thermal stability, chemically non-reactive, magnetically permeable, reduced energy band gaps, improved reusability, and simplified recovery. Moreover, BC-based photocatalytic nanocomposites showed reduced recombination rates of the electron-hole pairs which are desirable for photocatalytic applications. However, the surface areas of the composites are usually smaller than that of the BC but higher than those of the pristine photocatalysts. Practically, the performances of the nanocomposites are much superior to those of the corresponding pristine components. This hybrid treatment technology is an emerging field and its industrial application is still at an early stage of the investigation. Therefore, exploring the full potential and practical applications of this technology is highly encouraging. Hence, this review focused on the critical evaluation of the most recent research on the synthesis, characterization, and photocatalytic treatment efficiency of the BC photocatalyst nanocomposites towards emerging pollutants in the aqueous medium. Moreover, the influence of various sources of BC feedstocks and their limitations on adsorption and photodegradation activities are discussed in detail. Finally, concluding remarks and future research directions are given to assist and shape the exploration of BC-based nanocomposite photocatalysts in water treatment.
生物炭（BC）-光催化剂纳米复合材料作为一种有吸引力的水和废水处理技术而出现。这些纳米复合材料受益于吸附和光催化的协同效应，从而提高了水中和废水中污染物的去除率。在本综述中，考虑了三种基于 BC 的纳米复合材料光催化剂，如 BC-TiO、BC-ZnO 和 BC 尖晶石铁氧体。这些纳米复合材料获得了内在特性，以改善原始 BC 和光催化剂的实际局限性。基于 BC 的纳米复合材料获得了高光催化活性、机械硬度、热稳定性、化学惰性、磁性渗透性、减小的能带隙、提高的可重复使用性和简化的回收性。此外，基于 BC 的光催化纳米复合材料表现出电子-空穴对的复合率降低，这对于光催化应用是理想的。然而，复合材料的比表面积通常小于 BC，但大于原始光催化剂。实际上，纳米复合材料的性能远优于相应的原始组件。这种混合处理技术是一个新兴领域，其工业应用仍处于研究的早期阶段。因此，探索该技术的全部潜力和实际应用具有很高的意义。因此，本综述重点评价了关于基于 BC 的光催化剂纳米复合材料在水介质中新兴污染物的合成、表征和光催化处理效率的最新研究的关键评价。此外，详细讨论了各种 BC 原料来源及其对吸附和光降解活性的限制的影响。最后，给出了结论和未来的研究方向，以协助和塑造 BC 基纳米复合材料光催化剂在水处理中的探索。
