Stable CuCrO2 nanoparticles - ZnO fibres p-n heterostructure system for effective photocatalytic activity

Heterostructured photocatalysts were fabricated by coupling electrospun n-type ZnO fibres and hydrothermally derived p-type CuCrO2 nanoparticles. The effect of the amount of CuCrO2 nanoparticles on the photocatalytic activity of the heterostructured photocatalyst was systematically investigated. The formation of the heterojunctions between the two semiconductors was revealed via detailed XRD, XPS, TEM and optical property measurements. The experimental results indicated that the optimal CuCrO2 amount in the composite photocatalyst was 1.0wt.% due to the optimum doping and surface coverage, higher absorption onset edge, larger absorption intensity and optimum band gap energy. This composite photocatalyst, fabricated by drop casting of CuCrO2 nanoparticle dispersion on ZnO fibres, displayed 30% higher rate constant (k) value compared to the pure ZnO fibres in the degradation of methylene blue dye molecules and reached 93.4% decomposition in 1 h under UV-visible light exposure. The obtained results are highly encouraging in comparison to only UV/light active p-n heterostructured photocatalysts previously reported in literature. Therefore, we believe that the proposed approach here opened the way for simple synthesis of highly-efficient visible light active heterostructured semiconductor photocatalyst systems.

Download Full-text

Visible-light active tin selenide nanostructures: synthesis, characterization and photocatalytic activity

New Journal of Chemistry ◽

10.1039/c7nj04030j ◽

2017 ◽

Vol 41 (23) ◽

pp. 14689-14695 ◽

Cited By ~ 13

Author(s):

Muhammad Naeem Ashiq ◽

Samia Irshad ◽

Muhammad Fahad Ehsan ◽

Sidra Rehman ◽

Saima Farooq ◽

...

Keyword(s):

Methylene Blue ◽

Photocatalytic Activity ◽

Reaction Mechanism ◽

Visible Light ◽

Blue Dye ◽

Methylene Blue Dye ◽

Tin Selenide ◽

Mechanism Of Degradation ◽

Visible Light Active

Photocatalytic activity and proposed reaction mechanism of degradation of Methylene Blue dye by SnSe nanostructures.

Download Full-text

Photocatalytic Reduction of CO2 to Methanol by Cu2O/TiO2 Heterojunctions

Sustainability ◽

10.3390/su14010374 ◽

2021 ◽

Vol 14 (1) ◽

pp. 374

Author(s):

S.-P. Cheng ◽

L.-W. Wei ◽

H.-Paul Wang

Keyword(s):

Solar Energy ◽

Visible Light ◽

Uv Light ◽

Light Exposure ◽

Photocatalytic Reduction ◽

Low Carbon ◽

Mild Conditions ◽

Photogenerated Electrons ◽

Visible Light Active ◽

Reduction Of Co2

The conversion of CO2 to low-carbon fuels using solar energy is considered an economically attractive and environmentally friendly route. The development of novel catalysts and the use of solar energy via photocatalysis are key to achieving the goal of chemically reducing CO2 under mild conditions. TiO2 is not very effective for the photocatalytic reduction of CO2 to low-carbon chemicals such as methanol (CH3OH). Thus, in this work, novel Cu2O/TiO2 heterojunctions that can effectively separate photogenerated electrons and holes were prepared for photocatalytic CO2-to-CH3OH. More visible light-active Cu2O in the Cu2O/TiO2 heterojunctions favors the formation of methanol under visible light irradiation. On the other hand, under UV-Vis irradiation for 6 h, the CH3OH yielded from the photocatalytic CO2-to-CH3OH by the Cu2O/TiO2 heterojunctions is 21.0–70.6 µmol/g-catalyst. In contrast, the yield of CH3OH decreases with an increase in the Cu2O fraction in the Cu2O/TiO2 heterojunctions. It seems that excess Cu2O in Cu2O/TiO2 heterojunctions may lead to less UV light exposure for the photocatalysts, and may decrease the conversion efficiency of CO2 to CH3OH.

Download Full-text

Hydrothermal Synthesis and Enhanced Photocatalytic Activity of TiO\(_{2}\)-Fe@CNTs Nanocomposite for Methylene Blue Degradation under Visible Light Irradiation

Communications in Physics ◽

10.15625/0868-3166/24/4/5676 ◽

2015 ◽

Vol 24 (4) ◽

pp. 363

Author(s):

Le Ha Chi ◽

Pham Duy Long ◽

Nguyen Van Chuc ◽

Le Van Hong

Keyword(s):

Methylene Blue ◽

Photocatalytic Activity ◽

Visible Light ◽

Tio2 Nanoparticles ◽

Uv Light ◽

Band Gap Energy ◽

Nanocomposite Materials ◽

Light Irradiation ◽

Hydrothermal Route ◽

Methylene Blue Degradation

TiO2 is one of the most attractive metal oxides because of the excellent chemical and photocatalytic properties. However, a problem in the application of TiO2 is the large band gap energy of 3.2 eV, corresponding to its photocatalytic activity under UV-light irradiation of wavelengths <387 nm. In this work, TiO2 nanoparticles doped with iron were grown on the surface of functionalized carbon nanotubes (TiO2-Fe@CNTs) to expand the photoabsorbance of the nanocomposite materials in the visible light region and improve their photocatalytic activity. TiO2-Fe@CNTs nanocomposite materials were synthesized by hydrothermal route in Teflon-sealed autoclave at 180oC for 10h. The FE-SEM and X-Ray diffraction measurements were taken for morphology and structural analysis of TiO2 nanoparticles doped with Fe coating on CNTs. The effects of the iron and CNTs on the enhanced photocatalytic activity for methylene blue degradation under AM 1.5 illumination of 100 mW.cm−2 were investigated.

Download Full-text

Synthesis of AgCl/BiOCl Composite Photocatalyst and its Photocatalytic Activity under Visible-Light Irradiation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.662.372 ◽

2013 ◽

Vol 662 ◽

pp. 372-378 ◽

Cited By ~ 3

Author(s):

Li Shan Zhang ◽

Teng Fa Long ◽

Chang Qi Yan ◽

Xing Cun He ◽

Meng Lin Cheng ◽

...

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Uv Light ◽

Raw Materials ◽

Kinetic Studies ◽

Significant Loss ◽

Halogen Lamp ◽

Composite Photocatalyst ◽

Hydrolysis Method ◽

First Order Kinetics

A series of BiOCl photocatalysts with different AgCl contents have been synthesized by a simple hydrolysis method at room temperature using BiCl3 and Bi(NO3)3•5H2O as the main raw materials. The resulting products were characterized with X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and UV‐vis diffuse reflectance spectra (DRS). The photocatalytic activities of these AgCl/BiOCl composites were evaluated by the degradation of rhodamine B (RhB) under UV and visible light. The results revealed that the BiOCl/AgCl with an initial 100:1 mole ratio of Bi to Ag have the highest photocatalytic activity. RhB (20 mg/L) was decolorized by 98.81% in 15 min under sun light, in contrast to 95.89% and 11.63% in 30 min under halogen lamp and UV light, respectively. The catalysts did not show any significant loss of activity after 19 recycles for the photodegradation of RhB, suggesting the photocatalyst is essential stable. Kinetic studies showed that the RhB photocatalytic degradation followed pseudo-first order kinetics reaction and fit the Langmuir-Hinshelwood kinetic equation. The rate controlling step was absorption reaction.

Download Full-text

Physical Properties of Fe3+/TiO2 Nanoparticles and Photocatalytic Disinfection of Foodborne Microorganisms

Current Topics in Nutraceutical Research ◽

10.37290/ctnr2641-452x.17:312-321 ◽

2018 ◽

Vol 17 (3) ◽

pp. 312-321

Author(s):

Long Men ◽

Zhan Ge ◽

Sun Meng-Yun ◽

Zhuang Hong ◽

Wang Ran

Keyword(s):

Methylene Blue ◽

Photocatalytic Activity ◽

Visible Light ◽

Physical Properties ◽

Salmonella Typhimurium ◽

Uv Light ◽

Meat Products ◽

Blue Dye ◽

Methylene Blue Dye ◽

Photocatalytic Disinfection

In this article, we studied the preparation of Fe3+/TiO2 nanoparticles and the photocatalytic disinfection effects of two typical foodborne microorganisms, a gram-negative bacterium (Salmonella typhimurium) and a gram-positive bacterium (Listeria monocytogenes), in meat products. The physical properties of Fe3+/TiO2 nanoparticles embedded with various levels of Fe3+ (0%–10%) and synthesized through an impregnation process were investigated using X-ray diffraction, transmission electron microscopy, and UV-vis spectrophotometer, and their photocatalytic activities were evaluated by measuring the degradation of methylene blue dye and the disinfection of foodborne pathogens S. typhimurium and L. monocytogenes under visible light and UV light. Fe3+ ions were found to be scattered across TiO2 surfaces or across TiO2 crystal lattices as microcrystals. However, the capacity for TiO2 nanoparticles to absorb visible light was significantly enhanced after they were embedded with.Fe3+/TiO2 nanoparticles with molar ratios (R) of Fe3+ to TiO2 of 0.001:1, 0.005:1, and 0.01:1 exhibited higher levels of methylene blue dye photocatalytic degradation and higher levels of foodborne pathogen photocatalytic disinfection than the TiO2 control. However, nanoparticles containing >1% Fe3+ exhibited lower levels of photocatalytic activity than the TiO2 control. Salmonella typhimurium was more resistant to the nano-Fe3+/TiO2 treatment than L. monocytogenes under visible and UV light conditions. These experiments demonstrate that embedding Fe3+ in TiO2 nanoparticles does not remarkably influence the TiO2 nanoparticle size or structure. Embedding appropriate levels of Fe3+ content (0.1%–1%) can enhance the photocatalytic activity of TiO2 nanoparticles.

Download Full-text

Sodium Tungsten Oxide Bronze Nanowires Bundles in Adsorption of Methylene Blue Dye under UV and Visible Light Exposure

Energies ◽

10.3390/en14051322 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1322

Author(s):

Kunyapat Thummavichai ◽

Le Anh Thi ◽

Swee-Yong Pung ◽

Oluwafunmilola Ola ◽

Mian Zahid Hussain ◽

...

Keyword(s):

Methylene Blue ◽

Visible Light ◽

Uv Light ◽

Light Exposure ◽

Blue Dye ◽

Methylene Blue Dye ◽

Adsorption Effect ◽

Sodium Tungsten ◽

Oxide Bronze ◽

Enhanced Adsorption

This paper describes the analysis and characterization of NayWOx bronze nanowires bundles and evaluation of their effective adsorption of methylene blue dye (MB). The Na-doped WOx bronze nanowires bundles were first synthesized via a simple solvothermal method, which were then fully characterized by using different techniques including TEM, XRD, XPS and UV-Vis, to validate the successful Na+ insertion into the WOx framework. The adsorption activities of the resulting NayWOx bronze nanowires bundles, compared with the undoped WOx form, were investigated by evaluating the adsorption effect on methylene blue under both UV and visible light irradiations. An enhanced adsorption performance of the Na-doped WOx bronze samples was recorded, which demonstrated a 90% of removal efficiency of the MB under different conditions (dark, visible and UV light). Moreover, the NayWOx bronze samples also offered a 4 times better kinetic rate of MB removal than the plain WOx nanowires.

Download Full-text

Tuning the Photocatalytic Performance of Plasmonic Nanocomposites (ZnO/Aux) Driven in Visible Light

Current Catalysis ◽

10.2174/2211544708666190124114519 ◽

2019 ◽

Vol 8 (1) ◽

pp. 56-61

Author(s):

Aneeya K. Samantara ◽

Debasrita Dash ◽

Dipti L. Bhuyan ◽

Namita Dalai ◽

Bijayalaxmi Jena

Keyword(s):

Electron Transfer ◽

Photocatalytic Activity ◽

Visible Light ◽

Transfer Rate ◽

Photocatalytic Performance ◽

Light Exposure ◽

Au Nanoparticle ◽

Electron Transfer Rate ◽

Au Nps ◽

Zno Nanostructure

: In this article, we explored the possibility of controlling the reactivity of ZnO nanostructures by modifying its surface with gold nanoparticles (Au NPs). By varying the concentration of Au with different wt% (x = 0.01, 0.05, 0.08, 1 and 2), we have synthesized a series of (ZnO/Aux) nanocomposites (NCs). A thorough investigation of the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface has been carried out. It was observed that ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity among all concentrations of Au on the ZnO surface, which degrades the dye concentration within 2 minutes of visible light exposure. It was further revealed that with an increase in the size of plasmonic nanoparticles beyond 0.08%, the accessible surface area of the Au nanoparticle decreases. The photon absorption capacity of Au nanoparticle decreases beyond 0.08% resulting in a decrease in electron transfer rate from Au to ZnO and a decrease of photocatalytic activity. Background: Due to the industrialization process, most of the toxic materials go into the water bodies, affecting the water and our ecological system. The conventional techniques to remove dyes are expensive and inefficient. Recently, heterogeneous semiconductor materials like TiO2 and ZnO have been regarded as potential candidates for the removal of dye from the water system. Objective: To investigate the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface and the effect of the size of Au NPs for photocatalytic performance in the degradation process. Methods: A facile microwave method has been adopted for the synthesis of ZnO nanostructure followed by a reduction of gold salt in the presence of ZnO nanostructure to form the composite. Results: ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity which degrades the dye concentration within 2 minutes of visible light exposure. The schematic mechanism of electron transfer rate was discussed. Conclusion: Raspberry shaped ZnO nanoparticles modified with different percentages of Au NPs showed good photocatalytic behavior in the degradation of dye molecules. The synergetic effect of unique morphology of ZnO and well anchored Au nanostructures plays a crucial role.

Download Full-text

Green Synthesis of ZnO/Dy/NiO Heterostructures for Enhanced Photocatalytic Applications

Journal of Photocatalysis ◽

10.2174/2665976x01666200214125616 ◽

2020 ◽

Vol 1 (1) ◽

pp. 30-36

Author(s):

Shubha Jayachamarajapura Pranesh ◽

Diwya Lanka

Keyword(s):

Visible Light ◽

Uv Light ◽

Combustion Method ◽

Hybrid Nanocomposites ◽

Synthetic Dyes ◽

Hybrid Nanostructure ◽

Wide Range ◽

Visible Light Active ◽

Textile Industries ◽

Photocatalytic Applications

Background: Textile industries discharge harmful synthetic dyes to nearby water sources. These colour effluents should be treated before discharge to reduce the toxicity caused by synthetic colours. Objective: To synthesize visible light active superstructures to reduce water pollution caused by textile industries. Methods: We have successfully synthesized ZnO/Dy/NiO hybrid nanocomposites using waste curd as fuel by a simple combustion method. The obtained material was able to reduce recombination and enhanced the photocatalytic degradation of organic pollutants. The as-synthesized material was characterized by XRD, absorption spectroscopy, FESEM, EDAX, etc. The obtained hybrid nanostructure was used as a photocatalyst for the degradation of methylene blue under sunlight, UV light as well as in dark. Comparative experiments were carried out with a variation of catalytic load, pH, dye concentrations, etc. for a better understanding of the performance of the catalyst at various conditions. Results and Conclusion: The ternary compound shows wide range of absorption by expanding absorption band both in UV and visible regions. ZnO/Dy/NiO hybrid nanocomposites performed well and showed uniqueness in the activity uder visible light.

Download Full-text