Comparison of the photocatalytic performance of TiO2/AC and TiO2/CNT nanocomposites for methyl orange photodegradation

2018 ◽  
Vol 78 (5) ◽  
pp. 1082-1093 ◽  
Author(s):  
Liping Wang ◽  
Jingru Guo ◽  
Jingjing Dang ◽  
Xiaojun Huang ◽  
Si Chen ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Performance ◽  
Chloride Ion ◽  
Degradation Efficiency ◽  
Ion Concentration ◽  
Nano Tio2 ◽  
Ultraviolet Wavelength ◽  
Nanotube Composites

Abstract To enhance the photocatalytic degradation efficiency of TiO2 on methyl orange (MO) removal, TiO2/AC (activated carbon) and TiO2/CNT (carbon nanotube) composites were synthesized. The prepared catalysts were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The photocatalytic performance of the obtained composites were investigated by the degradation of MO under UV irradiation (254 nm, 365 nm). The results revealed that the prepared nanocomposite showed higher MO degradation efficiency than pure nano-TiO2. Additionally, batch experiments of influencing factors, including H2O2 dosage, metal dopants, inorganic anions, chloride ion concentration and ultraviolet wavelength on the MO removal efficiency were also conducted. The results demonstrated that metal dopant and the presence of H2O2 significantly enhanced MO removal efficiency.

Preparation and Photo-catalytic Activity of Cu-Supported Nano-TiO2

2020 ◽  
Vol 1 (1) ◽  
pp. 38-42
Author(s):  
Jun Yan
Keyword(s):  
Catalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Nano Tio2 ◽  
Hydrolysis Method ◽  
Response Range ◽  
Photo Response ◽  
Forced Hydrolysis ◽  
Visible Photocatalytic Activity

Cu-supported nano-TiO2 catalyst was prepared by forced hydrolysis method under mild condition. The morphology, composition and optical absorption properties of the samples were characterized by means of scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectroscopy (UV-VIS DRS). Visible photocatalytic activity of the samples was investigated by photocatalytic degradation experiment on methyl orange. The results indicated that nano-TiO2 was about 20nm in size with the main form of anatase, and photo response range was significantly broadened after it was loaded on the surface of Cu. The sample possessed high visible light catalytic activity, with the degradation rate of methyl orange reaching 94% under simulated natural light.

scholarly journals Photocatalytic activity of Cu2O/ZnO nanocomposite for the decomposition of methyl orange under visible light irradiation

2019 ◽  
Vol 26 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Xian-sheng Wang ◽  
Yu-duo Zhang ◽  
Qiao-chu Wang ◽  
Bo Dong ◽  
Yan-jia Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
Methyl Orange Solution ◽  
Degradation Efficiency ◽  
X Ray ◽  
Transmission Electron ◽  
Consistent Performance ◽  
Two Phases

AbstractZnO is modified by Cu2O by the process of precipitation and calcination. X-ray diffraction has shown that Cu2O/ZnO catalysts are made of highly purified cubic Cu2O and hexagonal ZnO. Scanning electron microscopy and transmission electron microscopy have shown that ZnO adhered to the surface of Cu2O. Due to the doping of Cu2O, the absorption range of the Cu2O/ZnO catalyst is shifted from the ultraviolet to the visible region due to diffuse reflection. X-ray photoelectron spectroscopy and photoluminescence spectra have confirmed that there is a substantial interaction between the two phases of the resultant catalyst. The degradation efficiency of Cu2O/ZnO on methyl orange solution is obviously enhanced compared to Cu2O and ZnO. The maximum degradation efficiency is 98%. The degradation efficiency is affected by the pH of the solution and initial concentration. After three rounds of recycling, the degradation rate is almost same. This shows a consistent performance of Cu2O/ZnO. The increase in catalytic ability is related to the lattice interaction caused by the doping of Cu2O.

scholarly journals Electrochemical redox treatment of denitrification in coastal secondary effluent using Ti/IrO2 anode

2021 ◽  
Author(s):  
Yaozong Zhang ◽  
Bo Pang
Keyword(s):  
Removal Efficiency ◽  
Treatment Plant ◽  
Chloride Ion ◽  
Ion Concentration ◽  
Secondary Effluent ◽  
Low Carbon ◽  
Cathodic Potential ◽  
Nitrate N ◽  
N Removal ◽  
Electrochemical Redox

Abstract In northern coastal industrial park, inlet of the wastewater treatment plant (WWTP) had the characteristics of low carbon source and high chloride ion concentration, which resulted in its poor biodegradability. In this case, the experiment explored an electrochemistral method to remove nitrogen. Cathodic potential, Ti/IrO2 was confirmed as the anode and − 1.6V was taken as the potential in order to remove nitrate-N. The findings include: when the initial chloride ion was 2000 and 3000 mg/L, the effect on the removal difference of nitrogen was slight. When the electrolysis time was 60 min, ammonia-N was removed completely, nitrite-N concentration kept 1mg/L approximately. The ammonia-N removal efficiency went up with the increasing cathodic potential, and was completely removed in different water samples, but nitrate-N removal showed an opposite result. The production amount of nitrite-N was the least at -1.6V. As the pH increased, ammonia-N and nitrate-N’s removal efficiency went up first and then down, the removal effect was the best at pH being 9, Nitrite-N was less influenced by pH. After optimizing the raw water sample, Nitrate-N and TN removal efficiency were significantly increased, but the nitrite-N almost kept constant.

scholarly journals Preparation and Properties of CaCO3-Supported Nano-TiO2 Composite with Improved Photocatalytic Performance

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3369
Author(s):  
Jie Wang ◽  
Sijia Sun ◽  
Lei Pan ◽  
Zhuoqun Xu ◽  
Hao Ding ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
Interaction Mechanism ◽  
Pure Tio2 ◽  
Degradation Efficiency ◽  
Nano Tio2 ◽  
Composite Photocatalyst ◽  
Tio2 Particles ◽  
Grinding Machine

In order to improve the photocatalytic degradation efficiency of nano-TiO2, reduce its usage and realize recycling and reuse, CaCO3–TiO2 composite photocatalyst was prepared with calcium carbonate (CaCO3) and TiO2 in a grinding machine through the integration of grinding depolymerization, dispersion and particle composition. The photocatalytic degradation performance, recycling performance, structure and morphology of CaCO3–TiO2 were studied. The interaction mechanism between CaCO3 and TiO2 and the improvement mechanism for the photocatalytic performance of TiO2 were also discussed. The results show that under the UV light irradiation for 20 and 40 min, the degradation efficiency of methyl orange by the composite photocatalyst with 40% TiO2 (mass fraction) was 90% and 100%, respectively. This was similar to that of pure TiO2, and the performance of the composite photocatalyst was almost unchanged after five cycles. CaCO3–TiO2 is formed by the uniform loading of nano-TiO2 particles on the CaCO3 surface, and the nano-TiO2 particles are well dispersed. Due to the facts that the dispersion of nano-TiO2 is improved in the presence of CaCO3 and the charge transport capability is improved through the interfacial chemical bonds between CaCO3 and TiO2, the formation of this complex is an intrinsic mechanism to improve the photocatalytic efficiency of nano-TiO2 and reduce its usage in application processes.

scholarly journals TiO2/Halloysite Composites Codoped with Carbon and Nitrogen from Melamine and Their Enhanced Solar-Light-Driven Photocatalytic Performance

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Pengcheng Yao ◽  
Shuhui Zhong ◽  
Zhurui Shen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photocatalytic Performance ◽  
Weight Ratio ◽  
Halloysite Nanotubes ◽  
Degradation Efficiency ◽  
Solar Light ◽  
Potential Candidate ◽  
X Ray ◽  
Ft Ir ◽  
C And N

Carbon (C) and nitrogen (N) codoped anatase TiO2/amorphous halloysite nanotubes (C+N-TiO2/HNTs) were fabricated using melamine as C and N source. The samples prepared by different weight ratios of melamine and TiO2were investigated by X-ray diffraction (XRD) and UV-vis diffuse reflectance spectrometer. It is shown that the doping amounts of C and N could influence the photocatalytic performance of as-prepared composites. When the weight ratio of melamine/TiO2is 4.5, the C+N-TiO2/HNTs exhibited the best photocatalytic degradation efficiency of methyl blue (MB) under solar light irradiation. The obtained C+N-TiO2/HNTs were characterized by transmission electron microscopy (TEM), N2adsorption-desorption isotherm (BET), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrum (FT-IR). The results showed that the aggregation was effectively reduced, and TiO2nanoparticles could be uniformly deposited on the surface of HNTs. This leads to an increase of their specific surface area. XPS and FT-IR analyses indicated TiO2particles were doped successfully with C and N via the linkage of the Ti–O–N, O–Ti–N, and Ti–O–C. Photocatalytic experiments showed that C+N-TiO2/HNTs had higher degradation efficiency of MB than TiO2/HNTs. This makes the composite a potential candidate for the photocatalytic wastewater treatment.

scholarly journals A Review on Synthesis and Characterization of Ag2O Nanoparticles for Photocatalytic Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Workneh M. Shume ◽  
H. C. Ananda Murthy ◽  
Enyew Amare Zereffa
Keyword(s):  
Visible Light ◽  
Organic Pollutants ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Photocatalytic Performance ◽  
Organic Dyes ◽  
Metal Oxide Nanoparticles ◽  
Ion Concentration ◽  
X Ray ◽  
Ag2o Nanoparticles

Even though the photocatalytic processes are a good technology for treatment of toxic organic pollutants, the majority of current photocatalysts cannot utilize sunlight sufficiently to realize the decomposition of these organic pollutants. As stated by various researchers, metal oxide nanoparticles have a significant photocatalytic performance under visible light source. Among various chemical and physical methods used to synthesize nanostructured silver oxide, green synthetic route is a cheaper and environmental friendly method. To confirm the optimum production of Ag2O NPs, effect of pH, extract concentration, metal ion concentration, and contact time were optimized. The structure, morphology, crystallinity, size, purity, elemental composition, and optical properties of obtained Ag2O NPs were characterized by different techniques, such as scanning electron microscopy (SEM), transmission electron microscope (HRTEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and UV-visible spectrophotometer accordingly as revealed by our literature review. The photocatalytic performance of the synthesized nanocrystalline Ag2O by photocatalytic degradation of organic dyes under visible light irradiation has been discussed thoroughly in this review. Many past studies revealed that organic dyes and pollutants are decomposed completely by green synthesized Ag2O NPs under irradiation of visible light.

scholarly journals Photocatalytic Activity of Magnetic Nano-β-FeOOH/Fe3O4/Biochar Composites for the Enhanced Degradation of Methyl Orange Under Visible Light

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 526
Author(s):  
Zheng Zhang ◽  
Guanghua Wang ◽  
Wenbing Li ◽  
Lidong Zhang ◽  
Benwei Guo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Azo Dye ◽  
Photocatalytic Performance ◽  
Active Species ◽  
Step Method ◽  
Vis Spectroscopy

A novel nano-β-FeOOH/Fe3O4/biochar composite with enhanced photocatalytic performance and superparamagnetism was successfully fabricated via an environmentally friendly one-step method. The structural properties of the prepared composite were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, and a vibrating sample magnetometer. The XPS spectrum of the as-prepared composites confirmed the presence of Fe-O-C bonds between β-FeOOH and biochar, which could be conducive to transfer photo-generated electrons. UV-vis spectroscopy confirmed the existence of an electron–hole connection between β-FeOOH and biochar, which promoted the rapid interface transfer of photogenerated electrons from β-FeOOH to biochar. These novel structures could enhance the response of biochar to accelerate the photoelectrons under visible light for more free radicals. Electron spin resonance analysis and free radical quenching experiments showed that •OH was the primary active species in the photodegradation process of methyl orange by nano-β-FeOOH/Fe3O4/biochar. In the synergistic photocatalytic system, β-FeOOH/Fe3O4/biochar exhibited excellent catalytic activity for the degradation of azo dye (methyl orange), which is 2.03 times higher than that of the original biochar, while the surface area decreased from 1424.82 to 790.66 m2·g−1. Furthermore, β-FeOOH/Fe3O4/biochar maintained a stable structure and at least 98% catalytic activity after reuse, and it was easy to separate due to its superparamagnetism. This work highlights the enhanced photocatalytic performance of β-FeOOH/Fe3O4/biochar material, which can be used in azo dye wastewater treatment.

scholarly journals First Attempts of the Use of 195Pt NMR of Phenylbenzothiazole Complexes as Spectroscopic Technique for the Cancer Diagnosis

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3970 ◽  
Author(s):  
Bruna T. L. Pereira ◽  
Mateus A. Gonçalves ◽  
Daiana T. Mancini ◽  
Kamil Kuca ◽  
Teodorico C. Ramalho
Keyword(s):  
Cancer Treatment ◽  
Cancer Diagnosis ◽  
Density Functional ◽  
Chemical Shifts ◽  
Chloride Ion ◽  
Platinum Complexes ◽  
Dft Method ◽  
Ion Concentration ◽  
Implicit Solvent ◽  
Early Cancer Diagnosis

Platinum complexes have been studied for cancer treatment for several decades. Furthermore, another important platinum characteristic is related to its chemical shifts, in which some studies have shown that the 195Pt chemical shifts are very sensitive to the environment, coordination sphere, and oxidation state. Based on this relevant feature, Pt complexes can be proposed as potential probes for NMR spectroscopy, as the chemical shifts values will be different in different tissues (healthy and damaged) Therefore, in this paper, the main goal was to investigate the behavior of Pt chemical shifts in the different environments. Calculations were carried out in vacuum, implicit solvent, and inside the active site of P13K enzyme, which is related with breast cancer, using the density functional theory (DFT) method. Moreover, the investigation of platinum complexes with a selective moiety can contribute to early cancer diagnosis. Accordingly, the Pt complexes selected for this study presented a selective moiety, the 2-(4′aminophenyl)benzothiazole derivative. More specifically, two Pt complexes were used herein: One containing chlorine ligands and one containing water in place of chlorine. Some studies have shown that platinum complexes coordinated to chlorine atoms may suffer hydrolyses inside the cell due to the low chloride ion concentration. Thus, the same calculations were performed for both complexes. The results showed that both complexes presented different chemical shift values in the different proposed environments. Therefore, this paper shows that platinum complexes can be a potential probe in biological systems, and they should be studied not only for cancer treatment, but also for diagnosis.

scholarly journals ZnCDs/ZnO@ZIF-8 Zeolite Composites for the Photocatalytic Degradation of Tetracycline

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 934
Author(s):  
Yong Cheng ◽  
Xiuxiu Wang ◽  
Yu Mei ◽  
Dan Wang ◽  
Changchun Ji
Keyword(s):  
Catalytic Activity ◽  
Photocatalytic Degradation ◽  
Photocatalytic Performance ◽  
Active Species ◽  
Degradation Efficiency ◽  
Experimental Result ◽  
Porous Nanostructure ◽  
Resultant Material

Considering the photocatalytic performance of CDs, ZnO, and the unique porous nanostructure and stability of ZIF-8, we prepared ZnCDs/ZnO@ZIF-8 zeolite composites. The resultant material represented an enhanced ability for the photodegradation of TC compared with that of ZnCDs and ZnO. The photocatalytic degradation efficiency reached over 85%. The catalytic activity of the composites was maintained after four cycles. The experimental result indicated that ×O2 radical was the active species in the reaction.

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