Design of modified lafeo3 based photocatalyst for energy evolution and environmental abatement

Abstract

newlineIn the present trend of modern science, green approach towards environmental remediation newlineand energy production over visible light driven photocatalysts were the burning topics for the newlinescientific community. In this scenario, perovskite type semiconductors (LaFeO3) were on the newlinetop of the merit list due to their interesting properties and potential application. However, newlineLaFeO3 experience certain shortcoming such as photostability, charge recombination and low newlinesurface area etc. To alleviate these problems, several approaches have been made viz. surface newlinemodification, doping of metals/non-metals or by making composites with carbonaceous newlinematerials. According to Thirumalairajan et al. tuning of morphology plays an important role in newlinethe photocatalytic activity of the LaFeO3. Similarly, Wu et al. reported 87.9% phenol newlinedegradation by B-doped LaFeO3, which was still not satisfactory. Its journey towards industrial newlineapplication is hindered due to its fast charge recombination rate in a single-phase photocatalyst newlinebefore the photocatalytic reaction happen. To avoid the above confliction, LaFeO3 has assorted newlinewith other narrow-band gap semiconductors to construct heterostructured composite that newlineresults in better charge separation efficiency and broad light harvesting region. When LaFeO3 newlineforms heterostructure with other semiconductor of matching band energy potential, the newlinephotogenerated electrons or/and holes migrated from one semiconductor to other newlinesemiconductor reducing the charge pair recombination rate. newlineRGO loaded on LaFeO3 nano sphere (GLFO) has been designed with greater stability in order newlineto promote the photocatalytic activity towards water splitting by tuning the optical band gap of newlineLFO and reducing the e- and h+ recombination process (figure-1). To alleviate the charge newlinerecombination, an effective strategy is to employ reduced graphene oxide (RGO) as a charge newlinesink, separator and transporter. Gel combustion method has been adopted to prepare LFO nano newlinesphere and through ultrasonication LFO spheres was fabricated on RGO surface. When tested newline10 newlinethe photocatalyst towards hydrogen production under visible light, the rate of GLFO increases newlinemore than two fold than neat LFO. So as a case study, the GLFO photocatalyst can contribute a newlineremarkable outcome in the photocatalytic field. Formation mechanism, structural, optical and newlineelectronic properties of LaFeO3 nanosphere/RGO composite is discussed and correlated with newlinephotocatalyic activity. newlineFigure1: RGO loaded LaFeO3 nanocomposite showing enhanced hydrogen production newlineability under visible-light irradiation. newlineg-C3N4/LaFeO3 photocatatalyst, a mediator-free direct Z-scheme photocatalytic system by newlineusing mechanical mixing method with reliable interfacial interaction, the g-C3N4/LaFeO3 newlinenanocomposite were effectively fabricated, with reliable interfacial interaction and formed newlinegood heterojunction interaction between g-C3N4 and LaFeO3 which can considerably enhance newlinethe photocatalytic activity as compared to prinstine g-C3N4 and LaFeO3 (Figure-2). Here the newlinehigh HER (1152 and#956;molh-1g-1) is also supported by PL spectra, Mott-Schottky plot, newlineElectrochemical Impedance Spectroscopy (EIS) and solid-solid interfacial interaction. newlineThe effect of Zn-Cr layered double hydroxide on LaFeO3 has been studied. LaFeO3 (LFO) newlinedecorated Zn-Cr LDH nanocomposites was successfully synthesized by a facile in-situ newlinemethod. As compare to the neat LFO and LDH, the LDHLFO shows enhanced absorption of newlinevisible light and improvement in electron-hole separation efficiency. Moreover, introduction of newlineLDH to LaFeO3 shows higher photocurrent value than that of neat LFO and LDH exhibiting newlinehigher photocatalytic activity towards organic pollutant degradation and water reduction