Challenges and prospects of main-group metal-doped TiO2 photocatalysts for sustainable water remediation

The elimination of toxic organic pollutants from contaminated drinking water and industrial wastewater is a critical concern for ensuring sustainable living on Earth. The late 20th century's industrialization and the current relocation of large production facilities to rural areas have seriously affected the quality of surface and subsurface waters. The organic molecules that result from the processing of raw materials or the manufacturing of products are generally toxic and show high stability and resistance to degradation. When exposed to light, active nanomaterials can be used in photocatalysis, an inventive technique that adsorbs, breaks down, and eliminates organic contaminants. TiO2 is a well-known and robust photocatalyst that is often referred to as the industry standard. To maximize TiO2's solar-powered capabilities, scientists have been actively investigating metal cation doping to reduce the material's optical bandgap and improve its photocatalytic activity. However, in this pursuit, contradictory studies have surfaced about how main-group metal dopants affect the photocatalytic capabilities of TiO2. This review highlights recent advances in main-group metal-doped TiO2 photocatalysts for the removal of organic contaminants from water. These photocatalysts exhibit enhanced photocatalytic activity due to modifications in their physicochemical properties, including increased surface area, improved light absorption, and reduced electron-hole recombination. The photocatalytic performances of variously doped systems, providing a comprehensive analysis of their efficiencies and underlying effects, are compared. This study aims to provide insights into the design and application of high-performance photocatalysts for environmental remediation.