Nanocomposites for Water Treatment, Photocatalysis, and Challenges: A Systematic Review

The finite supply of water on this planet led researchers to investigate nanocomposites, which are unique compounds with great performance and many applications. Many researchers are now interested in photocatalytic degradation methods due to their ability to facilitate both spontaneous and non-spontaneous reactions using light energy. The review's objective is to explain what nanocomposites mean, their types, various preparation procedures, and various characterisation approaches, and to employ nanocomposites in catalytic applications for wastewater treatment. It also seeks to compile some of the research on this topic. Through bibliometric analysis, the lineage and the extent to which countries are interested in publishing research on this issue in various methods of narration are illustrated. Nanocomposites can be used as catalysts to remove more than 90% of Cr (VI) after 120 min, phosphate (99.77%), ammonia (65.65%), Nitrite (99.98%) and remove several dyes such as Direct Blue 14 (94.57%), Congo Red (90.23%), Sunset Yellow (83.56%), brilliant cresol blue (BCB) (98.80%), neutral red (NR) (98.33%), methylene blue (MB) (99.6%) and more. Finally, challenges faced by nanocomposites in wastewater treatment are analyzed and summarized.