Efficient Degradation of Methylene Blue Dye Over Highly Reactive Cu Doped Strontium Titanate (SrTiO3) Nanoparticles Photocatalyst Under Visible Light

Abstract

Visible light induced photocatalysts of Cu doped SrTiO3 (Cu/SrTiO3) nanoparticles with the size -60-75 nm were prepared via facile sol-gel method. The morphological, optical, crystalline properties and compositions of synthesized Cu/SrTiO3 nanoparticles were thoroughly characterized by field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD), ultra violet-visible spectroscopy (UV-Vis) and energy dispersive X-ray (EDX). A significant red shift in the UV-diffused reflectance spectrum was observed and the absorption edge shifted to visible region by the Cu doping. Surprisingly, the band gap of SrTiO3 was changed from 3.2 eV drop to 2.96 eV. The photocatalytic activity of the synthesized Cu/SrTiO3 nanoparticles was demonstrated for the degradation of Methylene Blue dye under visible light irradiation. The formation of new acceptor region in Cu/SrTiO3 was responsible for high photocatalytic activity of Cu/SrTiO3 nanoparticles. The results showed that the Methylene Blue dye was degraded by -66% within time span of 2 h over the Cu/SrTiO3 nanoparticles. This dye degradation reaction followed the Langmuir-Hinshelwood kinetics and also exhibited first order reaction rate. The calculated rate constant for the degradation reaction following first order kinetics was k = 0.0016 min(-1).

On the photocatalytic reduction of MTT tetrazolium salt on the surface of TiO2 nanoparticles: Formazan production kinetics and mechanism

“…In the semiconductor photocatalysis literature, many reactions involving organic compounds are considered to follow the LangmuirHinshelwood (L-H) kinetics [61][62][63][64], only few authors considering the necessity to tackle the fulfillment of the basic hypothesis and applicability requirements of the L-H model [65,66] before using its framework to analyze and interpret kinetics data. For reasons further discussed in this article, in the present study we used a general power-law form of the rate equation and determined reaction rates, partial reaction orders, and apparent rate constants, without referring to a particular kinetic model.…”

Efficient Photo-catalytic Degradation of Acid Red 183 dye in the presence of ZnO nano-whiskers

“…The as-synthesized ZnO nano-whiskers (ZNWs) were applied as photo-catalyst to investigate the photocatalytic degradation of Acid Red 183. oxidation and reduction reaction takes place at the surface of the semiconductor and if there the photogenerated electron-hole pair did not separate well there is possibility recombination of electron-hole pairs and this will diminish the efficiency of photocatalytic reaction [28][29][30]. According to this, the relevant reactions at the semiconductor surface causing the degradation of dyes can be expressed as follows [11] The recombination of electron-hole pairs is acting as one of major factor that is responsible for inefficiencies of the photocatalytic processes.…”

Effect of Bismuth Dopant on the Photocatalytic Properties of SrTiO3 Under Solar Irradiation

“…Dyes are a group of complex organic materials that usually are poisonous; they are resistant to biodegradation and are difficult to remove from the environment. The common biological methods are not effective to degrade the synthetic dyes due to their complex chain structures and high chemical stability [5][6][7][8]. For this reason, there are huge efforts for the development of new materials able to degrade dyes, above all materials that can be activated with solar light (photocatalyst), since it is considered a clean source of energy.…”