Study of the photoelectrochemical activity of ZnO: Ag/rGO photo-anodes synthesized by two-steps sol-gel method

Abstract This work investigate the influence of Silver Plasmon and reduced graphene oxide (rGO) on the photoelectrochemical performance (PEC) of ZnO thin films synthesized by the sol-gel method. The physicochemical properties of the obtained photo-anodes were systematically studied using several characterization techniques. The X-ray diffraction analysis showed that all samples presented hexagonal Wurtzite structure with apolycrystalline nature. Raman and EDX studies confirmed the existence of both Ag and rGO in ZnO: Ag/rGO thin films. The estimated grain size obtained from (SEM) analysis decreased with Ag doping, then increased to a maximum value after rGO addition. The UV-vis transmission spectra of the as-prepared ZnO: Ag and ZnO: Ag/rGO thin films have shown a reduction in the visible range with a redshift at the absorption edges. The bandgaps were estimated to be around 3.17, 2.7, and 2.52 eV for ZnO, ZnO: Ag, and ZnO: Ag/rGO, respectively. Moreover, the electrical measurements revealed that the charge exchange processes were enhanced at the ZnO: Ag/rGO/electrolyte interface, accompanied by an increase in the (PEC) performance compared to ZnO and ZnO: Ag photo-anodes. Consequently, the photocurrent density of ZnO: Ag/rGO (0.2 mA.cm-2) was around 4 and 2.22 times higher than photo-anodes based on undoped ZnO (0.05 mA.cm-2) and ZnO: Ag (0.09 mA.cm-2), respectively. Finally, from the flat band potential and donor density, deduced from the Mott-Schottky, it was clear that all the samples were n-type semiconductors with the highest carrier density for the ZnO: Ag/rGO photo-anode.

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The Photoelectrochemical Characteration of Porous Titania Dioxide Thin Films Prepared by PEG-Assisted Sol-Gel Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.943 ◽

2009 ◽

Vol 79-82 ◽

pp. 943-946

Author(s):

Ai Ping Wang ◽

Yan Sheng Yin ◽

Hong Feng Wang ◽

Zhi Bin Zhu ◽

Ming Hui He

Keyword(s):

Thin Films ◽

Cyclic Voltammetry ◽

Polyethylene Glycol ◽

Uv Light ◽

Sol Gel ◽

Tio2 Thin Films ◽

Photoelectrochemical Activity ◽

Gel Method ◽

Sol Gel Method ◽

Porous Titania

Nanocrystalline titania porous films were prepared on ITO and glass substrates by polyethylene glycol（PEG）-assisted sol-gel method using Ti(C4H9COO)4 as precursor, ethanol as solvent and NH(C2H2OH)2 as chelating agent and PEG 2000as a template. When the amount of polyethylene glycol is within the range of 0～2. 0g/L ,. The characteristics and microstructure of films as well as the chemical and physical changes taken place during so-gel and heat treatments were analyzed by XRD, SEM and Emission spectra. The Cyclic voltammetry which measurements the films by illumination with a high pressure mercury lamp are employed to analyze photoelectrochemical property the porous titania thin films. The effects of precursor concentration and PEG 2000 contention the characteristic of films were discussed. The Cyclic voltammetry experiment under UV light irradiation indicated that the pores in the TiO2 thin films enhanced its photoelectrochemical activity; the size of the pores thin films obviously affected the photo-current exchanged rate of titania films.

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Enhanced photoelectrochemical performance of Ti-doped hematite thin films prepared by the sol–gel method

Applied Surface Science ◽

10.1016/j.apsusc.2011.10.001 ◽

2012 ◽

Vol 258 (7) ◽

pp. 2307-2311 ◽

Cited By ~ 54

Author(s):

Xiaojuan Lian ◽

Xin Yang ◽

Shangjun Liu ◽

Ying Xu ◽

Chunping Jiang ◽

...

Keyword(s):

Thin Films ◽

Sol Gel ◽

Photoelectrochemical Performance ◽

Gel Method ◽

Sol Gel Method

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Regulations of aging time on optical properties of nano-crystalline ZnO thin films fabricated by sol–gel method

Functional Materials Letters ◽

10.1142/s1793604717500242 ◽

2017 ◽

Vol 10 (03) ◽

pp. 1750024

Author(s):

Jitao Li ◽

Dingyu Yang ◽

Xinghua Zhu ◽

Hui Sun ◽

Xiuying Gao ◽

...

Keyword(s):

Thin Films ◽

Optical Properties ◽

Aging Time ◽

Sol Gel ◽

Visible Region ◽

Zno Thin Films ◽

Visible Range ◽

Gel Method ◽

Sol Gel Method ◽

Nano Crystalline

Nano-crystalline Zinc oxide (ZnO) thin films on glass substrates have been fabricated by sol–gel method for different aging times. The thermal curve of the dried gel was examined and it was found that evaporation of solvent and the decomposition of the organics have completed before 250[Formula: see text]C. X-ray diffraction patterns and Atomic Force Microscope images of samples only have a small difference of microstructure. The transmittance spectra revealed high transmittance in visible region. The optical band gap of the samples remined stable (3.28[Formula: see text]eV). Also, the Urbach energy was calculated to explain the defect concentration. The Photoluminescence spectra in ultraviolet and visible regions were studied, and the decreased intensity of peaks at 387[Formula: see text]nm and the increased emissions in visible range were found. The results showed that excessive aging time can cause degeneration of optical properties of thin films.

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