Effect of doping in TiO/chitosan composite on adsorptive-photocatalytic removal of gallic acid from water.

Gallic acid (GA) has emerged as a low biodegradable and high acidity industrial effluent. Due to mutagenic and carcinogenic nature of GA, it becomes essential to remove it from wastewater. Different chemical, physical and biological methods are being used for this purpose. Photocatalytic degradation is found to be promising method. In the present study N-doped titanium oxide and chitosan composites are used for the photodegradation of gallic acid. An attempt has been made to combine C from chitosan with undoped and N-doped TiO so as to produce composites that can suppress the electron-hole recombination, and reduce band gap thus enhancing their catalytic and adsorptive properties. The morphology and surface properties of the synthesized material were determined using techniques such as FTIR, XRD, XPS, BET, PL and SEM-EDX. The formation of spherical TiO and N-doped TiO occurred in anatase phase, over chitosan. The TiO/chitosan (TC) and N- TiO/chitosan (NTC) composites exhibited outstanding photodegradation activity 81% and 92.2% for the GA under visible irradiation (λ > 400 nm) at acidic pH. The desired outcomes of the nitrogen and carbon doping in the metal oxide (NTC) include a highly homogenous surface, a lowered band gap, an increase in the material's surface area, improved reusability, and a decrease in photoluminescence, which suggests that the material's electron-hole recombination is delayed. The purpose of the current study is to gain an understanding of how doping (C/N) affects the development of a photocatalyst that may be used to remove GA from industrial effluent.