Rapid and morphology controlled synthesis of anionic S-doped TiO<sub>2</sub> photocatalysts for the visible-light-driven photodegradation of organic pollutants

Pei

et al. 2018

Sci Rep

The pure, tin (Sn)-doped, lanthanum (La)-doped and Sn/La co-doped titanium dioxide (TiO2) nanomaterials were synthesized using sol-gel method followed by calcination at the temperature of 360 °C, 450 °C and 600 °C, respectively. The structures of the nanomaterials were characterized by X-ray diffraction (XRD), Thermogravimetric (TG), Differential Thermal Analysis (DTA), Scanning Electron Microscopy (SEM), Energy Dispersive Spectrum (EDS), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectrum (XPS), Diffuse Reflectance Spectrum (DRS), Photoluminescence Spectrum (PL), Brunauer-Emmett-Teller Measurements (BET), respectively. The photocatalytic property of the photocatalysts under UV light was evaluated through the degradation of Rhodamine B (RhB). The results show that the anatase-rutile phase transition is promoted by Sn-doping while La-doping retards the phase transition. However, La doping plays a major role in the process of phase transformation. The photocatalytic activity of pure TiO2 is affected by annealing temperature remarkably and the optimal annealing temperature is 450 °C. The photocatalytic activity of TiO2 is enhanced significantly by Sn and La doping at three different temperatures. Sn/La-TiO2 exhibits the highest degradation rates and the fastest reaction rates probably owing to the synergistic effect of Sn4+ and La3+ ions in inhibiting the recombination of photogenerated electron-hole pairs. The formation of extra surface hydroxyl groups and additional surface area are also beneficial for the photocatalytic activity.

Section: Introductionmentioning

confidence: 99%

Preparation and characterization of Sn/La co-doped TiO2 nanomaterials and their phase transformation and photocatalytic activity

Pei

et al. 2018

Sci Rep

“…More pollutants were adsorbed onto the surface of the catalyst, providing more available areas for electron-hole pair separation. Bakar and Ribeiro [43] reported increased Methyl Orange removal with S BET of S-doped TiO 2 . The high surface area and the large porous channels of nanorods were among the factors for enhanced performance.…”

Section: Self-dopingmentioning

confidence: 97%

Impact of Doping and Additive Applications on Photocatalyst Textural Properties in Removing Organic Pollutants: A Review

et al. 2021

The effect of ion doping and the incorporation of additives on photocatalysts’ textural properties have been reviewed. Generally, it can be summarised that ion doping and additives have beneficial effects on photocatalytic efficiency and not all have an increase in the surface area. The excessive amount of dopants and additives will produce larger aggregated particles and also cover the mesoporous structures, thereby increasing the pore size (Pd) and pore volume (Pv). An excessive amount of dopants also leads to visible light shielding effects, thus influence photocatalytic performance. Ion doping also shows some increment in the surface areas, but it has been identified that synergistic effects of the surface area, porosity, and dopant amount contribute to the photocatalytic performance. It is therefore important to understand the effect of doping and the application of additives on the textural properties of photocatalysts, thus, their performance. This review will provide an insight into the development of photocatalyst with better performance for wastewater treatment applications.

“…[34] Sulfur (S) as a traditional dopant has been verified to be effective in modifying the TiO 2 for enhancing the photocatalytic performance. [35] When S atoms were introduced to TiO 2 , S 6 + and S 4 + states could replace Ti 4 + while S 2 + could replace O atoms. The formed impurity band can narrow the band gap and greatly enhance the electrons and holes separation efficiency.…”

Section: Introductionmentioning

confidence: 99%

One‐Pot Solvothermal Synthesis of Flower‐Like S‐Doped BiOCl for Enhanced Photocatalytic Property in Dye Degradation and Nitrogen Fixation

et al. 2021

Nowadays, environmental pollution and energy shortage have aroused people's wide concern. Here we report that S-doped BiOCl photocatalyst was successfully fabricated via a simple solvothermal process. The as-obtained S-doped BiOCl photocatalysts were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoemission spectroscopy (XPS), nitrogen adsorption-desorption, UV/Vis diffuse reflectance (DRS), and photoluminescence (PL) emission spectra. The photocatalytic performance of the S-doped BiOCl photocatalyst with different S contents was evaluated by the photocatalytic degradation of cationic dye (Rhodamine-B (RhB)) and anionic dye (Congo red (CR)). The results reveal that all the S-doped BiOCl samples possess better photocatalytic activity than pure BiOCl. Specifically, the degradation rate of S(6 %)-BiOCl sample for RhB and CR was 99 % and 90 %, respectively. Meanwhile, the photocatalytic nitrogen fixation performance of the S-doped BiOCl sample was investigated. The results show that the S(6 %)-BiOCl sample possesses an excellent NH 3 yield of 108.6 μmol g À 1 h À 1 . Moreover, the S(6 %)-BiOCl catalysts have excellent recyclability and stability. This work provides a facile and accessible pathway to design effective photocatalysts for both photocatalytic degradation and nitrogen fixation.