Shock-Induced C-N-S Tridoped TiO2 with Improved Photocatalytic Activity Under Visible Light

Abstract

Using metatitanic acid (H2TiO3) and thiourea (CN2H4S) as titanium precursor and dopant sourcerespectively, a visible-light responsiblenon-metalC-N-S tridoped TiO2 photocatalyst is prepared by shock loading. X-ray powderdiffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-visiblediffusereflectancespectroscopy (UV-Vis DRS)are employed to characterize thecrystalline structure,morphology,chemical composition and optical property of recovered samples.The results indicate the metatitanic acid transformsto pure anatase phase by shock wave and that theaverage size of particles is3-5 nm.The as-synthesized TiO2 nano-particles are well dispersedand possess large surface area (309.02m2/g), and the edge adsorptionwavelength of the samples exhibitsslight red shifts with corresponding energy gap reduced to 3.16 eV.Carbon forms carbonate on the surface of TiO2,N may coexist inthe forms of substituted N (N-O-Ti) and interstitial N (O-Ti-N) in TiO2, and S6+is incorporated into the lattice of TiO2through substituting titanium atoms.The photocatalyticactivities of the as-synthesized samples are evaluated for the degradation of Rhodamine B under simulatedsunlight irradiation.Results revealthat these C-N-StridopedTiO2exhibit higherphotocatalyticdegradation activities than that of undoped TiO2samples and achieve an 83% removal rate for RB dye under the visible light irradiation for 70min with the thiourea-to-metatitanic acid mass of 2:1 and flyervelocity 2.52 km·s-1,whichis mainly attributed to the synergistic effects of well-formed anatase phase, high specific surface area and band gap narrowing resulting from C-N-S tridoping.