Direct Z-scheme MgIn2S4/TiO2 heterojunction for enhanced photocathodic protection of metals under visible light

2022 ◽  
Author(s):  
Hong Li ◽  
Xingqiang Cui ◽  
Weizhe Song ◽  
Zhanyuan Yang ◽  
Yanhui Li ◽  
...  

Abstract To improve the photocathodic protection performance of traditional TiO2 photoanodes for metals, constructing a Z-scheme heterojunction is one of the most promising and creative strategies. Herein, we fabricated a novel Z-scheme MgIn2S4 nanosheets/TiO2 nanotube nanocomposite through anodization and hydrothermal method. The optimized Z-scheme MgIn2S4/TiO2 nanocomposites exhibited stronger visible light absorption, higher separation efficiency of photoelectrons and photocathodic protection performances in comparison to pure TiO2. The theoretical analysis and experimental results show that the Z-scheme heterojunction and oxygen vacancies jointly improved the separation efficiency of photogenerated electron-hole pairs and visible light absorption capacity, thereby improving the photoelectric conversion performance of the MgIn2S4/TiO2 nanocomposites. Furthermore, the influence of the precursor solution concentration on the photocathodic protection performances of the composites was investigated. As a result, when the concentration of magnesium source in the precursor solution was 0.06 mmol, the prepared MgIn2S4/TiO2-0.06 displayed the best photocathodic protection performance. In addition, the hydroxyl radicals (•OH) generated in the electron spin resonance (ESR) experiment verified the Z-scheme heterojunction mechanism of the MgIn2S4/TiO2 composite, and also demonstrated the excellent redox performance of the composite. This work provides valuable reference for the construction of high-performance Z-scheme heterojunctions for photocathode protection of metals.

2019 ◽  
Vol 48 (10) ◽  
pp. 3486-3495 ◽  
Author(s):  
Juying Lei ◽  
Bin Chen ◽  
Weijia Lv ◽  
Liang Zhou ◽  
Lingzhi Wang ◽  
...  

An inverse opal TiO2/g-C3N4 composite with excellent photogenerated electron–hole separation efficiency and enhanced visible light absorption efficiency was constructed.


RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7627-7632
Author(s):  
Kun Jiang ◽  
Jin Zhang ◽  
Rui Luo ◽  
Yingfei Wan ◽  
Zengjian Liu ◽  
...  

It is a great challenge to simultaneously improve the visible light absorption capacity and enhance photon-generated carrier separation efficiency of photocatalysts.


RSC Advances ◽  
2019 ◽  
Vol 9 (30) ◽  
pp. 17165-17178 ◽  
Author(s):  
Smilja Marković ◽  
Ivana Stojković Simatović ◽  
Sanita Ahmetović ◽  
Ljiljana Veselinović ◽  
Stevan Stojadinović ◽  
...  

Employing CTAB in the microwave synthesis of ZnO particles enables improvement of their visible light absorption capacity and photo(electro)catalytic activity.


2020 ◽  
pp. 174751982093867
Author(s):  
Zhen Zhang ◽  
Shao-dong Qin ◽  
Jing-yun Chen ◽  
Jing Li ◽  
Ai-hua Xing

The synthesis of surface defect TiO2-x nanobelts with excellent visible light absorption is important to reduce costs, increase stability, and improve photocatalytic activity. In this work, we report that nitrogen-doped surface defect TiO2-x nanobelts are synthesized by annealing pristine TiO2 nanobelts in Ar/H2 (95%/5%) atmosphere followed by subsequent heat treatment in NH3 at various temperatures. The aim is to study the effect of the extent of the N-doping amount in the lattice of TiO2-x nanobelts on light absorption and photocatalytic activity. Considering the increase in organic pollutants in wastewater, the photocatalytic activity is measured by degrading rhodamine B (RhB) dye in water. The results demonstrate that the calcination temperature affects the doping level of N, and the b-TiO2-N550 sample exhibits higher photocatalytic performance than that of other samples under visible-light irradiation for the degradation of rhodamine B, which is up to 96.11%. The enhancement is ascribed to the synergistic effect of N-doping and self-doping oxygen vacancy (which extend the visible light absorption) and the separation efficiency of photogenerated carriers, which improves the photocatalytic activity.


RSC Advances ◽  
2017 ◽  
Vol 7 (63) ◽  
pp. 40028-40033 ◽  
Author(s):  
Hao Xu ◽  
Zhixing Gan ◽  
Weiping Zhou ◽  
Zuoming Ding ◽  
Xiaowei Zhang

Insufficient visible light absorption and fast recombination of the photogenerated electron–hole pairs have seriously hampered the photocatalytic performance of graphitic carbon nitride (g-C3N4) up to now.


Nanoscale ◽  
2019 ◽  
Vol 11 (40) ◽  
pp. 18628-18639 ◽  
Author(s):  
Shengyao Wu ◽  
Yanqing Shen ◽  
Xu Gao ◽  
Yanyan Ma ◽  
Zhongxiang Zhou

SnN3 monolayer can conduct overall photocatalytic splitting of water and has ultra-high visible light absorption capacity.


Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>


2019 ◽  
Vol 2 (10) ◽  
pp. 7518-7526 ◽  
Author(s):  
Hanggara Sudrajat ◽  
Mitsunori Kitta ◽  
Nobuyuki Ichikuni ◽  
Hiroshi Onishi

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