Studies on TiO2/ZnO photocatalysed degradation of lignin

Abstract. Nanosized ZnO particles derived from chemical co-precipitation route were used for casting ZnO films by screen printing method followed by sintering at two different temperatures. The variation in structural, optical and electrical properties of these films with temperature have been investigated by XRD, SEM, FTIR, Raman, UV-VIS, EPR and four probe analytical techniques. XRD patterns of these films exhibit polycrystalline nature with hexagonal wurtzite structure and SEM images reveal the smooth, dense and without any cracks/damage porous surface morphology. Infrared transmission spectra shows peaks pertaining to Zn-O stretching modes and their multiphonon modes. While Raman spectra exhibited strong peaks of E 2 (high) phonon and overtone of surface phonon mode at 429 cm −1 and 1144 cm −1 respectively with weak components of LO and TO branches. The direct band gap energy of these films showed narrowing of band gap from 3.21 eV to 3.12 eV on increasing sintering temperature from 500 • C to 600 • C. DC conductivity measurements confirmed semiconducting behaviour and showed lowering of activation energy. EPR spectra showed single narrow line resonance signal of g-value ∼ 1.9469 due to oxygen vacancies which are produced during synthesis of ZnO nanoparticles by sol-gel process. These studies revealed that on increasing sintering temperature the crystallinity of the film improves with reduction in lattice deformations in these screen printed ZnO films.

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“…ZnO finds lots of applications in the field of electronic, optoelectronic devices, sensor, biomedical, energy, environment, etc. [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Investigation of physical properties of screen printed nanosized ZnO films for optoelectronic applications

Zargar

Arora

Hafiz

2015

Eur. Phys. J. Appl. Phys.

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“…The solar light was found to be more effective than other irradiation techniques for degrading dyes as reported by the previous studies (Kumar et al 2013;Kansal et al 2008). During exposure in sunlight, when the photons hit the nanoparticles present in the colloidal mixture, the electrons at the particle surface are excited (Yu et al 2012).…”

Section: Analysis Of Photocatalytic Activitymentioning

confidence: 65%

Photocatalytic activity of biogenic silver nanoparticles synthesized using yeast (Saccharomyces cerevisiae) extract

2014

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Synthesis of metallic and semiconductor nanoparticles through physical and chemical route is quiet common but biological synthesis procedures are gaining momentum due to their simplicity, cost-effectivity and ecofriendliness. Here, we report green synthesis of silver nanoparticles from aqueous solution of silver salts using yeast (Saccharomyces cerevisiae) extract. The nanoparticles formation was gradually investigated by UV-Vis spectrometer. X-ray diffraction analysis was done to identify different phases of biosynthesized Ag nanoparticles. Transmission electron microscopy was performed to study the particle size and morphology of silver nanoparticles. Fourier transform infrared spectroscopy of the nanoparticles was performed to study the role of biomolecules capped on the surface of Ag nanoparticles during interaction. Photocatalytic activity of these biosynthesized nanoparticles was studied using an organic dye, methylene blue under solar irradiation and these nanoparticles showed efficacy in degrading the dye within a few hours of exposure.

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“…Furthermore, we compared the photocatalytic performance of our samples to the values reported in the previous works. In the work carried out by Kansal et al, 42 the TiO 2 -ZnO composite (TiO 2 -ZnO = 1:1) in particle structure with the photocatalyst concentration of 1 g/L, needs 5 h to degrade ∼ 70 % lignin solution. In addition, Tian et al 43 have fabricated TiO 2 -ZnO particles and found they were able to degrade MO solution up to ∼ 73 % with the degradation time of 3 h (photocatalyst concentration of 0.5 g/L).…”

Section: Resultsmentioning

confidence: 99%

Atomic layer deposition of TiO2-nanomembrane-based photocatalysts with enhanced performance

et al. 2016

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In this study, TiO2 and TiO2-ZnO nanomembranes were fabricated by atomic layer deposition using the three-dimensionally porous template and their photocatalytic properties were investigated. The nanomembranes were firstly deposited onto the surface of polyurethane porous sponge templates (sacrificial templates), followed by a calcination at 500 or 800 °C. Three-dimensionally porous structures as a replica of the porous sponge templates were thus achieved. By a pulverizing process, the porous structures were broken into small pieces, which were then employed as photocatalyst. Experimental results show that the degree of crystallinity is raised by increasing of the nanomembrane thickness due to the increase of the grain size with minimizing the number of grain boundaries in the thicker nanomembrane, which is beneficial to enhance the photocatalysis efficiency. On the other hand, the photocatalytic activity can also be improved by TiO2-ZnO composite, due to lower electron-hole recombination possibility and better carrier conductivity.

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Studies on TiO2/ZnO photocatalysed degradation of lignin

Cited by 246 publications

References 25 publications

Investigation of physical properties of screen printed nanosized ZnO films for optoelectronic applications

Investigation of physical properties of screen printed nanosized ZnO films for optoelectronic applications

Photocatalytic activity of biogenic silver nanoparticles synthesized using yeast (Saccharomyces cerevisiae) extract

Atomic layer deposition of TiO2-nanomembrane-based photocatalysts with enhanced performance

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