Improved catalytic efficiency by N-doped TiO2 via sol gel under microwave irradiation: Dual applications in degradation of dye and microbes

Abstract

The present research is to develop a facile and a fast microwave irradiation method to synthesise uniform and well-defined nitrogen-doped TiO2 nanocatalysts through the microwave-assisted sol-gel method. Advanced spectroscopic and analytical techniques are to be used to investigate the characteristics of the prepared catalyst samples. The synthesised nanocatalyst's XRD analysis shows lattice fringes for anatase phases. The XPS reveals the electronic state and composition of the dopant, which is almost consistent with the practically added concentration of dopant. The spectral shift (red shift) to the visible light region was demonstrated by the UV-visible diffuse reflectance spectroscopy analysis. The results demonstrated that NT3M4 has a reduced band gap of 2.56 ​eV. The HRTEM images of the NT3M4 analysis illustrate nanoparticles of spherical shape with a particle size of 6.3 ​nm. The surface properties and elemental composition were studied by SEM analysis, which depicts the irregular and rough morphology of the nanocatalysts. According to the Brunauer-Emmett-Teller (BET) results, NT3M4has a large surface area of 103 m2/g1. Type IV isotherms indicate the presence of the mesoporous structure in the nitrogen adsorption-desorption isotherm. The synthesised nanocatalyst NT3M4 demonstrated the best photocatalytic ability under visible light, which enhanced the rate of degradation of indigo carmine dye within 70 ​min. NT3M4 also exhibits antibacterial and antifungal activity. Further, this catalyst shows almost equal activity with standard chloramphenicol. Thus, the current study suggests microwave-assisted sol-gel methods for fabricating N-TiO2 nanocatalysts with the best photocatalytic performance for the degradation of harmful organic pollutants and pathogens in the presence of visible light irradiation.