scholarly journals Copper-nanoparticle-dispersed amorphous BaTiO3 thin films as hole-trapping centers: enhanced photocatalytic activity and stability

RSC Advances ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 5045-5052 ◽  
Author(s):  
Su-Wei Zhang ◽  
Shun Li ◽  
Bo-Ping Zhang ◽  
Dongfang Yu ◽  
Zuotai Zhang ◽  
...  

The photocatalytic degradation activity and photoelectrochemical performance of amorphous BaTiO3 films can be improved after introducing Cu NPs, and the oxidation of Cu is strongly hindered when dispersing in the amorphous BaTiO3 films that serve as h+-trapping centers.

2018 ◽  
Vol 18 (3) ◽  
pp. 81-91 ◽  
Author(s):  
C. Lalhriatpuia

Nanopillars-TiO2 thin films was obtained on a borosilicate glass substrate with (S1) and without (S2) polyethylene glycol as template. The photocatalytic behaviour of S1 and S2 thin films was assessed inthe degradation of methylene blue (MB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the SEM, XRD, FTIR and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data confirmed that the TiO2 particles are in its anatase mineral phase. The SEM and AFM images indicated the catalyst is composed with nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of MB was well studied at wide range of physico-chemical parameters. The effect of solution pH (pH 4.0 to 10.0) and MB initial concentration (1.0 to 10.0 mg/L) was extensively studied and the effect of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of MB was demonstrated. The maximum percent removal of MB was observed at pH 8.0 beyond which it started decreasing and a low initial concentration of the pollutant highly favoured the photocatalytic degradation using thin films and the presence of several interfering ions diminished the photocatalytic activity of thin films to some extent. The overall photocatalytic activity was in the order: S2 > S1 > UV. The photocatalytic degradation of MB was followed the pseudo-first-order rate kinetics. The mineralization of MB was studied with total organic carbon measurement using the TOC (total organic carbon) analysis.


2018 ◽  
Vol 6 (1) ◽  
pp. 22-30
Author(s):  
C. Lalhriatpuia ◽  
◽  
Thanhming liana ◽  
K. Vanlaldinpuia

The photocatalytic activity of Nanopillars-TiO2 thin films was assessed in the degradation of Bromophenol blue (BPB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the XRD, SEM and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data showed anatase phase of TiO2 particles with average particle size of 25.4 and 21.9 nm, for S1 and S2 catalysts respectively. The SEM and AFM images indicated the catalyst composed with Nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The average height of the pillars was found to be 180 and 40 nm respectively for the S1 and S2 catalyst. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of BPB using the UV light was studied at wide range of physico-chemical parametric studies to determine the mechanism of degradation as well as the practical applicability of the technique. The batch reactor operations were conducted at varied pH (pH 4.0 to 10.0), BPB initial concentration (1.0 to 20.0 mg/L) and presence of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of BPB. The maximum percent removal of BPB was observed at pH 6.0 and a low initial concentration of the pollutant highly favours the photocatalytic degradation using thin films. The presence of several interfering ions suppressed the photocatalytic activity of thin films to some extent. The time dependence photocatalytic degradation of BPB was demonstrated with the pseudo-first-order rate kinetics. Study was further extended with total organic carbon measurement using the TOC (Total Organic Carbon) analysis. This demonstrated an apparent mineralization of BPB from aqueous solutions.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Carlos Díaz-Uribe ◽  
Jose Viloria ◽  
Lorraine Cervantes ◽  
William Vallejo ◽  
Karen Navarro ◽  
...  

In this work, we synthesized Ag nanoparticles on TiO2 thin films deposited on soda lime glass substrates. Ag nanoparticles were synthesized by photoreduction under UV irradiation silver nitrate solution. X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) measurements were used for physicochemical characterization. The structural study showed that all samples were polycrystalline, main phases were anatase and rutile, and no additional signals were detected after surface modification. Raman spectroscopy suggested that silver aggregates deposited on the TiO2 films could exhibit the surface plasmon resonance (SPR) phenomenon; XPS and SEM analysis confirmed TiO2 film morphological modification after photoreduction process. Photocatalytic degradation of methylene blue (MB) was studied under UV irradiation in aqueous solution, and, besides, pseudo-first-order model was used to obtain kinetic information about photocatalytic degradation. Results indicated that Ag-TiO2 showed an important increase in photocatalytic activity under UV (from 20% to 35%); finally, Ag-TiO2 thin films had kapp value 2.4 × 10−3 ± 0.003 min−1 of 1.8 times greater than the kapp value 1.3 × 10−4 ± 0.0004 min−1 of TiO2 thin films.


CrystEngComm ◽  
2015 ◽  
Vol 17 (24) ◽  
pp. 4575-4583 ◽  
Author(s):  
Song Chengjie ◽  
Fan Mingshan ◽  
Hu Bo ◽  
Chen Tianjun ◽  
Wang Liping ◽  
...  

A g-C3N4-sensitized and NaNbO3-substrated II-type heterojunction with enhanced photocatalytic activity was synthesized.


2013 ◽  
Vol 700 ◽  
pp. 71-74
Author(s):  
Rui Ma ◽  
Wen Jie Zhang

Ce, Nd and Gd doped strontium titanate nanomaterial was prepared by a sol-gel method. Effects of transition metals doping on photocatalytic activities of the prepared materials were studied. The pure strontium titanate had photocatalytic degradation activity of 31.0%. The maximum degradation rate happened at Ce content of 20% and nearly 32.5% of the initial methyl orange was degraded on the material after 30 min of irradiation. Although there was a slight variation of photocatalytic degradation rate with the increasing Nd doping content, the materials doped with Nd had lower photocatalytic activity compared with pure strontium titanate. Nearly all the samples doped with Gd in the range up to 30% had much lower activity that the pure strontium titanate.


NANO ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. 1850127 ◽  
Author(s):  
Chentao Zou ◽  
Zhiyuan Yang ◽  
Mengjun Liang ◽  
Yunpeng He ◽  
Yun Yang ◽  
...  

Bi metal deposited on Bi2MoO6 composite photocatalysts have been successfully synthesized via a simple reduction method at room temperature with using NaBH4 as the reducing agent. The photocatalytic activity of the composite was evaluated by degradation of rhodamine B (RhB) and bisphenol A (BPA) solution under visible light. The rate constant of Bi/Bi2MoO6 composite to RhB is 10.8 times that of Bi2MoO6, and the degradation rate constant of BPA is 6.9 times of that of Bi2MoO6. Nitrogen absorption–desorption isotherm proved that the increase of specific surface area is one of the reasons for the improvement of photocatalytic degradation activity of Bi/Bi2MoO6 composites. The higher charge transfer efficiency of Bi/Bi2MoO6 is found through the characterization of the photocurrent and impedance, which are attributed to the surface plasmon resonance (SPR) effect produced by the introduction of the metal Bi monomer in the composite. Free radical capture experiments proved that cavitation is the main active species. Based on the above conclusions, a possible mechanism of photocatalytic degradation is proposed.


2021 ◽  
Author(s):  
Velayutham Shanmuganathan ◽  
Jayaraj Santhosh Kumar ◽  
Raman Pachaiappan ◽  
Paramasivam Thangadurai

The objective of this work was to study the effect of transition metal ion doping (1 wt% of Mn, Fe, Co, Ni, and Cu) in indium oxide (In2O3) on its photocatalytic activity to degrade organic dyes, which are considered potential environment pollutants.


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 733
Author(s):  
Dikra Bouras ◽  
Abla Mecif ◽  
Abdelhamid Harabi ◽  
Régis Barillé ◽  
Abdel hakim Mahdjoub ◽  
...  

Different percentages of CuO and ZnO were added into a local kaolin ceramic-based powder (DD3) with and without ZrO2. The modified powders were first characterized, then, a test for the photocatalytic degradation of dyes with orange II (OII) was carried out. The DD3 powders that were obtained with the addition of ZrO2, ZnO, and CuO, were prepared by two different methods and have shown a large and very fast photocatalytic activity. Discoloration ratios of about 93.6% and 100% were reached after 15 min and 45 min, for CuO and ZnO respectively. Finally, an alternative photocatalysis mechanism, based purely on chemical reaction processes, is proposed. The photocatalysis results with modified powders are compared with the results obtained with thin films, made with the same materials.


2013 ◽  
Vol 864-867 ◽  
pp. 715-718 ◽  
Author(s):  
Xiang Qing Li ◽  
Zhen Hong ◽  
Shi Zhao Kang ◽  
Li Xia Qin ◽  
Guo Dong Li ◽  
...  

TiO2 nanotubes were obtained by calcining at various temperatures. The influence of calcination temperature on the degradation activity of TiO2 nanotubes for Cr (VI) was investigated under UV light irradiation. It was found that the photocatalytic activity of TiO2 nanotubes calcinated at 350 °C was the highest. Furthermore, the photocatalytic activity of TiO2 nanotubes was higher than that of the P25 TiO2 nanoparticles. Importantly, the stability of TiO2 nanotubes for the degradation of Cr (VI) was high, and degradation efficiency can still reach 72.4% after 8 recycles. Consequently, a highly stable and active photocatalyst for degradation of Cr (VI) was achieved.


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