An inverse opal TiO2/g-C3N4 composite with a heterojunction for enhanced visible light-driven photocatalytic activity

2019 ◽  
Vol 48 (10) ◽  
pp. 3486-3495 ◽  
Author(s):  
Juying Lei ◽  
Bin Chen ◽  
Weijia Lv ◽  
Liang Zhou ◽  
Lingzhi Wang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Absorption Efficiency ◽  
Inverse Opal ◽  
Electron Hole ◽  
Visible Light Absorption ◽  
Visible Light Driven

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

scholarly journals A metal-free 3C-SiC/g-C3N4 composite with enhanced visible light photocatalytic activity

RSC Advances ◽  
2017 ◽  
Vol 7 (63) ◽  
pp. 40028-40033 ◽  
Author(s):  
Hao Xu ◽  
Zhixing Gan ◽  
Weiping Zhou ◽  
Zuoming Ding ◽  
Xiaowei Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Carbon Nitride ◽  
Photocatalytic Performance ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Visible Light Absorption ◽  
Metal Free ◽  
Visible Light Photocatalytic

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.

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 ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Precursor Solution ◽  
Absorption Capacity ◽  
Photoelectric Conversion ◽  
Visible Light Absorption ◽  
Photocathodic Protection ◽  
Protection Of Metals

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.

scholarly journals Improving the photocatalytic activity of nitrogen-doped surface defect TiO2-x nanobelts for degradation of organic pollutants

2020 ◽  
pp. 174751982093867
Author(s):  
Zhen Zhang ◽  
Shao-dong Qin ◽  
Jing-yun Chen ◽  
Jing Li ◽  
Ai-hua Xing
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Organic Pollutants ◽  
Rhodamine B ◽  
Light Absorption ◽  
Surface Defect ◽  
Separation Efficiency ◽  
Visible Light Absorption ◽  
Nitrogen Doped ◽  
N Doping

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.

Synthesis of Er-doped Bi2WO6 and enhancement in photocatalytic activity induced by visible light

RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 94887-94894 ◽  
Author(s):  
Meng Wang ◽  
Ziyu Qiao ◽  
Minghao Fang ◽  
Zhaohui Huang ◽  
Yan'gai Liu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Er Doped

1.5% Bi2WO6:Er3+ exhibited highest photocatalytic activity as the separation efficiency of the photogenerated electron–hole pairs is enhanced.

scholarly journals Synergistic effect of Ni–Ag–rutile TiO2 ternary nanocomposite for efficient visible-light-driven photocatalytic activity

RSC Advances ◽  
2020 ◽  
Vol 10 (60) ◽  
pp. 36930-36940 ◽  
Author(s):  
Petri M. Leukkunen ◽  
Ekta Rani ◽  
Assa Aravindh Sasikala Devi ◽  
Harishchandra Singh ◽  
Graham King ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Synergistic Effect ◽  
Visible Light ◽  
Light Absorption ◽  
Charge Separation ◽  
Effective Charge ◽  
Energy Dispersive ◽  
Intimate Contact ◽  
Visible Light Absorption ◽  
Visible Light Driven

Robust photocatalytic activity of Ni–Ag–RTiO2 is attributed to the improved visible light absorption and effective charge separation due to intimate contact between Ni and RTiO2via Ag, as evidenced by Ti3+ in Ti 2p XPS and energy dispersive mapping.

scholarly journals Visible-Light Driven TiO2 Photocatalyst Coated with Graphene Quantum Dots of Tunable Nitrogen Doping

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 344 ◽  
Author(s):  
Xiong Sun ◽  
Hui-Jun Li ◽  
Nanquan Ou ◽  
Bowen Lyu ◽  
Bojie Gui ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Photocatalytic Performance ◽  
Light Emission ◽  
Graphene Quantum Dots ◽  
Visible Light Absorption ◽  
Visible Light Driven ◽  
Nitrogen Doped Graphene

Nitrogen doped graphene quantum dots (NGQDs) were successfully prepared via a hydrothermal method using citric acid and urea as the carbon and nitrogen precursors, respectively. Due to different post-treatment processes, the obtained NGQDs with different surface modifications exhibited blue light emission, while their visible-light absorption was obviously different. To further understand the roles of nitrogen dopants and N-containing surface groups of NGQDs in the photocatalytic performance, their corresponding composites with TiO2 were utilized to degrade RhB solutions under visible-light irradiation. A series of characterization and photocatalytic performance tests were carried out, which demonstrated that NGQDs play a significant role in enhancing visible-light driven photocatalytic activity and the carrier separation process. The enhanced photocatalytic activity of the NGQDs/TiO2 composites can possibly be attributed to an enhanced visible light absorption ability, and an improved separation and transfer rate of photogenerated carriers.

Synthesis and High Visible Light Photocatalytic Activity of Ternary Brookite-g-C3N4-BiOBr Composite

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050045
Author(s):  
Ning Liu ◽  
Huidong Xie ◽  
Jie Li ◽  
Yajuan Zhao ◽  
Na Wang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Rhodamine B ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Photocurrent Density ◽  
Electron Hole ◽  
Degradation Ratio ◽  
Loading Amount ◽  
Visible Light Photocatalytic

Brookite TiO2 was synthesized by a hydrothermal method, g-C3N4 was prepared by a pyrolytic method, brookite/g-C3N4 composites were prepared by a calcining method, and brookite/g-C3N4/BiOBr ternary composites were prepared by loading BiOBr on the surface of brookite/g-C3N4. XRD and XPS analysis of the composites confirmed the formation of brookite TiO2/g-C3N4/BiOBr. SEM and TEM results confirmed the as-prepared composites were nanosized. The optimum loading amount of BiOBr was 30%. The photocatalytic results showed that the brookite/g-C3N4/30%BiOBr composites degraded rhodamine B completely under visible light irradiation. The degradation ratio of brookite/g-C3N4/30%BiOBr toward rhodamine B was nearly 100% for 2[Formula: see text]h, which was much higher than that of brookite TiO2 and brookite/g-C3N4 catalysts. The reason for the improvement of photocatalytic activity might be because the composites promoted the formation of superoxide radicals and the separation efficiency of photogenerated electron-hole pairs. The photocurrent density of the brookite/g-C3N4/30%BiOBr was about 10 times higher than that of pure brookite. In addition, the brookite/g-C3N4/BiOBr showed a good repeatablity of photocatalysis.

A simple method to synthesise Ag-doped TiO2 photocatalysts with different Ag0:Ag2O atomic ratios for enhancing visible-light photocatalytic activity

2017 ◽  
Vol 41 (8) ◽  
pp. 475-483 ◽  
Author(s):  
C. Chen ◽  
X. F. Lei ◽  
M. Z. Xue
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Absorption ◽  
Separation Efficiency ◽  
Visible Region ◽  
Light Irradiation ◽  
Electron Hole ◽  
X Ray

Pure anatase TiO2 photocatalysts with different Ag contents were prepared via a simple sol-gel method. The as-prepared anatase Ag-doped TiO2 photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, UV-Vis diffuse reflectance spectra, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, thermal gravity and differential thermal analysis, scanning electron microscopy and N2 adsorption–desorption measurements (BET). Compared with pure TiO2, Ag-doped anatase TiO2 photocatalysts exhibited not only increases in light absorption in the visible region, the separation efficiency of electron–hole pairs and surface area, but also inhibition of the titania phase transition from anatase to rutile. Photoreduction results showed that Ag-doped anatase TiO2 photocatalysts have greatly improved photocatalytic activity, compared with pure TiO2, and the reduction of Cr(VI) under visible light irradiation was much higher than that of pure TiO2. The optimum Ag content was 1.0 mol%, which led to the complete reduction of Cr(VI) under visible light irradiation (λ > 420 nm) for 4 h. The enhanced photocatalytic activity was attributed to the synergic effect of the pure anatase structure, and the increased light absorption in the visible region, separation efficiency of electron–hole pairs and atomic ratio of Ag0:Ag2O.

Novel Z-scheme visible-light-driven Ag3PO4/Ag/SiC photocatalysts with enhanced photocatalytic activity

2015 ◽  
Vol 3 (8) ◽  
pp. 4652-4658 ◽  
Author(s):  
Zhihong Chen ◽  
Fan Bing ◽  
Qiong Liu ◽  
Zhengguo Zhang ◽  
Xiaoming Fang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Efficient Separation ◽  
Excellent Photocatalytic Activity ◽  
Visible Light Driven

The excellent photocatalytic activity of Ag3PO4/Ag/SiC can be ascribed to the efficient separation of photogenerated electron–hole pairs through the Z-scheme.

Effect of Hydrogen Peroxide on the Photocatalytic Decomposition of 4-Nitrophenol over TiO2/Cr-Ti- MCM-41 Catalysts in Visible Light

2005 ◽  
Vol 486-487 ◽  
pp. 13-16
Author(s):  
Gun Dae Lee ◽  
Y.J. Do ◽  
Seong Soo Park ◽  
Seong Soo Hong
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Photocatalytic Decomposition ◽  
Electron Hole ◽  
Visible Light Absorption ◽  
Photocatalytic Activities ◽  
Hole Recombination ◽  
Mcm 41 ◽  
Uv Range

Cr, Ti-substituted TiO2-loaded MCM-41 (TiO2/Cr-Ti-MCM-41) catalysts were prepared, and their photocatalytic activities for decomposition of 4-nitrophenol (4-NP) in visible light were studied. The effect of H2O2 on the photocatalytic decomposition of 4-NP was investigated. Tisubstituted MCM-41 exhibited an absorption in UV range, and the incorporation of both Ti and Cr in the MCM-41 framework created visible light absorption. The visible light absorption capability of TiO2/Cr-Ti-MCM-41 increased with increasing TiO2 loading. The photocatalytic activity of Cr- Ti-MCM-41 for degradation of 4-NP in visible light increased with increasing TiO2 loading up to 33 wt%. The addition of H2O2 enhanced the photocatalytic activity of 33 wt% TiO2/Cr-Ti-MCM-41 for decomposition of 4-NP in visible light. H2O2 was found to promote the adsorption of 4-NP on the Cr-Ti-MCM-41 surface, leading to increased reaction rate. In addition, H2O2 may act as an electron acceptor during photocatalytic reaction, thereby lowering the electron-hole recombination and increasing the efficiency of hole utilization.

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