Bismuth (Bi) is a versatile metal widely utilized in various fields, particularly in catalysis. It forms composites with different metals, serving as efficient photocatalysts. These bismuth-based composites are crafted through innovative methods like sol-gel, microwave, and co-precipitation using nanotechnology. They exhibit remarkable photocatalytic prowess, degrading organic substances and detecting heavy metals through UV, sunlight, and visible light irradiation. Notable heavy metals such as Pb, arsenic, titanium, Cr, and Ni, along with organic pollutants like MB, CO, AO, NP, malonic acid, and diphenylhydrazine, have been detected using these composites. Bismuth's transitional nature contributes to its promising photocatalytic abilities. A comprehensive review spanning 1963 to 2019 highlights bismuth's exceptional efficacy as a photocatalyst for wastewater treatment. Bi-TNT (bismuth-titanate nanotube) composites, synthesized via one-step or two-step anodization methods, Demonstrate increased photocatalytic performance in treating industrial wastewater using visible light. The composites are analyzed using techniques including FE-SEM, EDS, XRD, UV-Vis DRS, and XPS for characterization purposes. Their improved photodegradation results are attributed to bismuth deposition.