Pyrocatechol violet sensitized Ho-TiO₂/ZnO nanostructured material: as photoanode for dye sensitized solar cells

Abstract

In this work TiO 2 , Holmium doped (Ho-TiO 2 ) Titanium oxide nanoparticles (NPs) and the corresponding nanostructured combinations (Ho-TiO 2 /ZnO NC) were successfully synthesized through sol gel method and reflux techniques respectively. The prepared nano materials were characterized with the help of x-ray diffraction Analysis (XRD), UV-visible spectroscopy, Scanning Electron Microscopy (SEM), Energy dispersive x-ray Analysis (EDX) and Fourier Transform infrared spectroscopy (FT-IR). The absorption spectra of nano materials were used for band gaps calculation. The band gap of pure TiO 2 NPs was found to be 3.10 eV which was effectively tuned to 2.65 eV by the doping of Holmium at different concentrations. XRD patterns confirmed the crystalline nature and purity of the synthesized nano materials. Morphology and elemental composition of the material were investigated using SEM and EDX respectively. FTIR helped in detecting the functional groups and grafting of the dye on the surface of nanoparticles. The nano materials were used as Photo-anodes in dye sensitized solar cells (DSSC). Pyrocatechol Violet dye was used as a photo-sensitizer. P3HT (polymer), a hole conducting polymer, was employed as a solid state electrolyte. I-V measurements were used for characterization of fabricated solar cells. Ho-TiO 2 /ZnO nanomaterial photosensitized with Pyrocatechol violet dye gave the highest percentage efficiency of 1.51. Other characteristic parameters of the fabricated devices such as short circuit current (Jsc), open circuit voltage (Voc), maximum power point (Mpp) and fill factor were found to be 11.2 mA cm −2 , 0.41 V, 1.55(mW cm −2 ) and 0.33 respectively.

Electrochemical Sensor for Detection and Degradation Studies of Ethyl Violet Dye

“… where α denotes the absorption coefficient, h is the photon’s energy, A is the proportionality constant, and n is the electronic transition with 3% Ho/TiO 2 NPs n = 1/2; therefore, the calculated band gap is 2.77 eV. 29 , 30 …”

“…The aqueous suspension of the synthesized sample reveals an absorption peak at 311 nm, with a fundamental absorption edge at 520 nm. The energy gaps of holmium-doped TiO 2 were calculated by using a Tauc plot (Figure B). where α denotes the absorption coefficient, h is the photon’s energy, A is the proportionality constant, and n is the electronic transition with 3% Ho/TiO 2 NPs n = 1/2; therefore, the calculated band gap is 2.77 eV. , …”

Characterization and bioactivities of M. arvensis, V. officinalis and P. glabrum: In-silico modeling of V. officinalis as a potential drug source

“…The presence of Phenols, Flavonoids, Steroids, Glycosides, Alkaloids, Tannins, Plobatannins, Anthocynins, Leucoanthocynins, Couramins and Anthraquinones in the herbal extracts was evaluated by different phytochemical tests mentioned in table: Si-1 ( Roghini and Vijayalakshmi, 2018 ).The functional groups of the organic compounds were characterized by FT-IR spectroscopy (Bruker Platinum ATR) in the range of 4000 to 500 cm −1 in the selected plants extract ( Ullah et al, 2020a , Ullah et al, 2020b ). The proximate analysis of the respective plants was conducted using a spectrophotometer (Cecil CE-7400) with 2 mm width slit using 10 mm cell under UV–Vis light from 200 to 800 nm wavelength to calculate the band gap with the help of absorption spectra.…”

“…Coccidiosis is economically important disease in poultry sector, causes US $ 3 billion loss annually ( Pawestri et al, 2020 , Quiroz-Castaneda and Dantan-Gonzalez, 2015 ) and almost US $ 0.8 billion is spent on prophylactic in-feed drugs ( Allen and Fetterer, 2002 ). In Pakistan, avian coccidiosis was not studied enough but institutional-based surveys revealed 32.79% prevalence on average in fecal and litter observation, the molecular study confirmed the presence of E. tenella, E. acervulina , E. necatrix, E maxima , E brunette, E. mitis and E. praecox ( Ayaz et al, 2003 , Khan et al, 2006 , Mustafa and Ali, 2005 , Abbas et al, 2015 , Sultana et al, 2009 , Bachaya et al, 2012 , Bachaya et al, 2015 , Awais et al, 2012 , Shamim et al, 2015 , Amin et al, 2014 , Rashid et al, 2019 , Ali et al, 2014 , Jamil et al, 2016 , Akram et al, 2018 , Naveed and Faryal, 2019 , Yousaf et al, 2018 , Sohail et al, 2019 , Khan, 2019 , Ullah et al, 2020a , Ullah et al, 2020b ). Eimeria spp are specific to different loci in the gastrointestinal tract of the avian host ( Lee and Lee, 2007 , Bachaya et al, 2015 ).…”

Surface Functionalization of Metal Oxide Semiconductors with Catechol Ligands for Enhancing Their Photoactivity

“…The catechol containing molecule boosted the efficiency of their device from 1.12% (for Ho–TiO 2 /ZnO) to 1.51% (for Ho–TiO 2 /ZnO/dye). [ 126 ] Adineh et al investigated DSSCs using dyes with catechol anchoring moiety and studied photogenerated electron injection mechanism in TiO 2 /catechol. They reported the high stability of catechol anchoring group on the TiO 2 surface and showed the DSSC fabricated using this catecholic dye have inconsiderable desorption of dye from the TiO 2 surface after days.…”