Solar light responsive TiO₂‐ZnO, modified with graphitic carbon nitride nano‐sheet for degradation of AB29

Abstract

BACKGROUND Photodegradation has drawn much attention in recent decades due to the technique’s ability to mineralize nonbiodegradable pollutants. Renewable energy sources, such as solar light energy, can be used to aid the reaction in the present of a solar light‐responsive photocatalyst. Mixed metal oxides (TiO2‐ZnO) modified with graphitic carbon nitride (gCNS‐3TiZn) were synthesized successfully and employed for the degradation of AB29 under artificial solar light. Ultrasonication–hydrothermal treatment was used to develop gCNS‐3TiZn. RESULTS Surface analysis investigation showed that the material is mesoporous with 5 nm pore diameter and 195 m2 g–1 surface area. The optical analysis showed successful reduction in the band gap of the material, making it capable of efficiently absorbing light energy in the visible wave region. The developed gCNS‐3TiZn was 3.33‐fold faster at AB29 degradation than the unmodified mixed oxides under the same reaction conditions, and this was attributed to the reduction in band‐gap energy of the catalyst resulting in a better absorption of solar light. It took 60 min to attain complete degradation of 50 ppm AB29 using 1.25 g L–1 gCNS‐3TiZn loading, whereas the AB29 degradation by the unmodified catalyst under the same conditions took 200 min to attain complete degradation. Recyclability study on gCNS‐3TiZn revealed that it can be used up to 10 cycles in the degradation of the selected pollutant without diminished performance. CONCLUSION The synthesized photocatalyst is a potential candidate for real wastewater treatment due to its reusability, stability and ability to utilize solar light as renewable energy source. © 2020 Society of Chemical Industry

Photocatalytic Activities of Siliceous Termite Hill‐Based Composites in Dye Degradation

“…However, the textural properties of ZnO-TH appeared to be better than those of TiO 2 -TH, which could be attributed to the even dispersion of the zinc on aluminosilicate layer of the TH. Nonetheless, pores were present on the surfaces of both catalysts, as evidenced by their increased surface areas, implying an improvement in their adsorption capacities and photocatalytic activities [2,12]. This result was similar to that reported by Hadjltaief et al [37], who modified Tunisian clay with ZnO, and found that the surface area of ZnO/natural clay improved after ZnO loading.…”

“…3b) to be 2.85 and 3.15 eV for TiO 2 -TH and ZnO-TH, respectively. It has been widely reported that pure TiO 2 anatase and rutile have bandgaps of 3.20 and 3.03 eV [12,35], respectively, whereas pure ZnO has a bandgap of 3.50 eV [2]. However, the bandgap energies obtained for the synthesized photocatalysts in this study indicated successful deposition of semiconductors on the surface of the support material, which improved their optical properties and enhanced their photocatalytic activities [34].…”

“…Also, the higher photocatalytic activity of TiO 2 -TH compared to ZnO-TH could be attributed to bands that promote electron and hole transfer while preventing recombination [18]. Moreover, TiO 2 has high pigmentary properties, light absorption, and is very stable in aqueous solution of any pH, as opposed to ZnO, which can easily be corroded in acidic medium, which could explain why TiO 2 -TH performed better than ZnO-TH in the degradation of MB dye [12]. This finding was similar to that of Alakhras et al [29], who found that zeolite/TiO 2 composite had excellent photocatalytic performance with a high degradation rate constant, outperforming zeolite/ZnO composite by a factor of three.…”

“…UV light poses more health risks than visible light and is more expensive to produce [3]. At the moment, there is a lot of interest in the development of visible-light-active photocatalysts [12]. According to Hamza et al [3], visible-light-responsive photocatalysts can efficiently use solar irradiation because approximately 46 % of solar light falls within the visible region, but only approximately 5 % within the UV region.…”

Facile Preparation of Carbon Nitride-ZnO Hybrid Adsorbent for CO2 Capture: The Significant Role of Amine Source to Metal Oxide Ratio

“…Compared to a pure melamine-based C 3 N 4 (CN500), the sample displayed a better adsorption capacity, as in Figure 6c. Similar to a study by Zheng and co-workers, the incorporation of urea created a disturbance during C 3 N 4 formation, thus providing a higher sheet gap and a better surface area [33][34][35][36]. To note, all hybrid samples in this study applied the combination of melamine and urea as the amine source to boost the sheet gap and surface contact area.…”