Band structure tuning of ZnO/CuO composites for enhanced photocatalytic activity

Mubeen, Khalida; Irshad, Afshan; Safeen, Akif; Aziz, Uzma; Safeen, Kashif; Ghani, Tayyaba; Khan, Kamran; Ali, Zulfiqar; Haq, İhsan Ul; Shah, Attaullah

doi:10.1016/j.jscs.2023.101639

Cited by 39 publications

(10 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Water 2023, 15, x FOR PEER REVIEW 15 of 21 trapping sites for electrons and holes, which are generated when ZnO is exposed to light. Without these defects, the electrons and holes can quickly recombine and lose their energy, reducing the efficiency of the photocatalytic process [51,52]. When Co and Gd are doped into ZnO, they can create additional oxygen vacancies in the lattice.…”

Section: Photocatalytic Activitymentioning

confidence: 99%

Tuning the Optical Properties of ZnO by Co and Gd Doping for Water Pollutant Elimination

Safeen

Safeen²,

Arif³

et al. 2023

Water

Self Cite

View full text Add to dashboard Cite

In the present study, pure, Co, Gd, and Co/Gd di-doped ZnO nanoparticles were synthesized via the co-precipitation synthesis route. The prepared samples were characterized through different techniques such as the X-ray diffraction method (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy, photoluminescence (PL)spectroscopy, and an impedance analyzer and vibrating sample magnetometer (VSM). The XRD pattern shows ZnO’s wurtzite hexagonal crystal structure; moreover, the shifting of characteristic peaks toward the lower angle indicates the inclusion of Co and Co/Gd in the ZnO host lattice. SEM micrographs show various morphologies such as rods, the agglomeration of particles, and spherical nanoparticles. The UV-Vis spectroscopy reveals that the absorption increased in the visible region and there was a substantial redshift for the doped samples. The bandgap decreased from 3.34 to 3.18 eV for the doped samples. The PL spectra show near-edge and inter-band transitions; the origin of inter-band transitions is attributed to the defect states present within the bands. The dielectric constant is strongly frequency dependent and decreases with Co and Co/Gd doping, while the electrical conductivity increases. A VSM study indicates that pure ZnO is diamagnetic, while the Co and Co/Gd doped ZnO nanoparticles showed ferromagnetic behavior. Under UV-visible light irradiation, the Co/Gd-ZnO nanoparticles showed higher photocatalytic activity than the ZnO nanoparticles. The enhanced photocatalytic activity may be attributed to a decreased bandgap with doping.

show abstract

Section: Photocatalytic Activitymentioning

confidence: 99%

Tuning the Optical Properties of ZnO by Co and Gd Doping for Water Pollutant Elimination

Safeen

Safeen²,

Arif³

et al. 2023

Water

Self Cite

View full text Add to dashboard Cite

show abstract

“…14 Under mild and favorable conditions, photocatalytic technology can efficiently degrade and eventually convert to nonharmful minerals. 15 Various types of nanostructured materials such as semiconductors, 16,17 non-noble plasmonic metal, 18 metal oxides, 19,20 polymers, 21,22 composites, 23,24 etc., have been used for sunlightbased catalysis applications. Special focus has been placed on semiconductor-based photo-catalysts due to their unusual properties at the nanoscale.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Various types of nanostructured materials such as semiconductors, , non-noble plasmonic metal, metal oxides, , polymers, , composites, , etc., have been used for sunlight- based catalysis applications. Special focus has been placed on semiconductor-based photo- catalysts due to their unusual properties at the nanoscale .…”

Section: Introductionmentioning

confidence: 99%

Bismuth-Based Z-Scheme Heterojunction Photocatalysts for Remediation of Contaminated Water

Wakjira,

Gemta,

Kassahun

et al. 2024

ACS Omega

View full text Add to dashboard Cite

Agricultural runoff, fuel spillages, urbanization, hospitalization, and industrialization are some of the serious problems currently facing the world. In particular, byproducts that are hazardous to the ecosystem have the potential to mix with water used for drinking. Over the last three decades, various techniques, including biodegradation, advanced oxidation processes (AOPs), (e.g., photocatalysis, photo-Fenton oxidation, Fenton-like oxidation, and electrochemical oxidation process adsorption), filtration, and adsorption techniques, have been developed to remove hazardous byproducts. Among those, AOPs, photocatalysis has received special attention from the scientific community because of its unusual properties at the nanoscale and its layered structure. Recently, bismuth based semiconductor (BBSc) photocatalysts have played an important role in solving global energy demand and environmental pollution problems. In particular, bismuth-based Z-scheme heterojunction (BBZSH) is considered the best alternative route to overhaul the limitations of singlecomponent BBSc photocatalysts. This work aims to review recent studies on a new type of BBZSH photocatalysts for the treatment of contaminated water. The general overview of the synthesis methods, efficiencyenhancing strategies, classifications of BBSc and Z-scheme heterojunctions, the degradation mechanisms of Z-and S-schemes, and the application of BBZSH photocatalysts for the degradation of organic dyes, antibiotics, aromatics compounds, endocrinedisrupting compounds, and volatile organic compounds are reviewed. Finally, challenges and the future perspective of BBZSH photocatalysts are discussed.

show abstract

“…[4,5] Semiconductor materials like TiO 2 and ZnO are widely used in photocatalysts, solar cells and sensors. [6][7][8] However, due to the inherent property defects of ZnO and TiO 2 , there are some problems in the photocatalytic process, such as easy recombination of carriers and low redox reaction efficiency. It has been reported that the existence of hexagonal ilmenite type ZnTiO 3 in ZnO/TiO 2 composites can improve the characteristics of reduction potential and low oxidation potential, which has great potential in photocatalysis, and similar to other photocatalysts, it can inhibit the recombination rate of photogenerated electrons and holes.…”

Section: Introductionmentioning

confidence: 99%

“…Currently, the research on semiconductor photocatalysts face issues such as expensive raw materials, complicated synthesis steps, and low degradation efficiency, which greatly limited them in practical applications [4,5] . Semiconductor materials like TiO 2 and ZnO are widely used in photocatalysts, solar cells and sensors [6–8] . However, due to the inherent property defects of ZnO and TiO 2 , there are some problems in the photocatalytic process, such as easy recombination of carriers and low redox reaction efficiency.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Catechol Sensitized Hollow Microspheres ZnTiO₃/TiO₂/ZnO for the Photodegradation of Methylene Blue

Yu,

Ma,

et al. 2024

ChemistrySelect

View full text Add to dashboard Cite

Designing new materials that can be used to treat environmental pollutants is one of the prime focuses of chemical science. Here, an unprecedented photocatalytic material with high activity of catechol sensitized ZnTiO3/TiO2/ZnO hollow microspheres was synthesized by hydrothermal method. The structure and properties of the composite photocatalyst were analyzed by various testing methods. The photocatalytic activity was evaluated by using methylene blue (MB) as the target degradation substance. The results demonstrated that catechol (CA) sensitized ZnTiO3/TiO2/ZnO photocatalyst is a hollow microsphere with a diameter of 1–1.5 mm, the CA molecules are covalently bonded to the ZnTiO3/TiO2/ZnO surface, and the composite photocatalyst has good light absorption and carrier separation performance. Under the condition of irradiation for 90 min, the degradation rate of the composite photocatalyst for MB was higher than that of ZnTiO3/TiO2/ZnO. When the loading amount of CA was 0.6 wt%, the degradation rate of CA/ZnTiO3/TiO2/ZnO for MB was as high as 98.28 %, and the reaction rate constant was up to 4.35×10−2 min−1. A reasonable mechanism of photocatalytic degradation of pollutants by catechol as sensitizer on ZnTiO3/TiO2/ZnO was proposed. This study provides a theoretical reference for efficient photodegradation of pollutants in the environment.

show abstract

Band structure tuning of ZnO/CuO composites for enhanced photocatalytic activity

Cited by 39 publications

References 58 publications

Tuning the Optical Properties of ZnO by Co and Gd Doping for Water Pollutant Elimination

Tuning the Optical Properties of ZnO by Co and Gd Doping for Water Pollutant Elimination

Bismuth-Based Z-Scheme Heterojunction Photocatalysts for Remediation of Contaminated Water

Fabrication of Catechol Sensitized Hollow Microspheres ZnTiO₃/TiO₂/ZnO for the Photodegradation of Methylene Blue

Contact Info

Product

Resources

About

Band structure tuning of ZnO/CuO composites for enhanced photocatalytic activity

Cited by 39 publications

References 58 publications

Tuning the Optical Properties of ZnO by Co and Gd Doping for Water Pollutant Elimination

Tuning the Optical Properties of ZnO by Co and Gd Doping for Water Pollutant Elimination

Bismuth-Based Z-Scheme Heterojunction Photocatalysts for Remediation of Contaminated Water

Fabrication of Catechol Sensitized Hollow Microspheres ZnTiO3/TiO2/ZnO for the Photodegradation of Methylene Blue

Contact Info

Product

Resources

About

Fabrication of Catechol Sensitized Hollow Microspheres ZnTiO₃/TiO₂/ZnO for the Photodegradation of Methylene Blue