Lignocelluloses Modified TiO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; Nanomaterials as Renewable Photocatalyst for Water Splitting

Yilkal Dessie Sintayehu

doi:10.11648/j.ijpp.20180201.12

Abstract

Photocatalytic water splitting process is a hopeful means to solve depletion and environmental pollution problems caused by fossil fuels as well as for sustainable hydrogen production using renewable natural resources like sunlight and biomass (cotton stalk). In this study the aim was to fabricate cotton stalk extracted Lignocellulose (LGO) Titanium oxide (TiO2) nanoparticles via sol-gel in ethanol and to investigate their photocatalytic water splitting activities under Visible light irradiation. Hence, in this study the opportunity for structural development of lignocellulose (LGO) modified TiO2 nanomaterial towards highly efficient and realistic photocatalysis applications are evidently abundant after improved light absorption, charge-carrier dynamics, and improved particle size porosity that benefits photocatalysis functionalities. LGO-TiO2 nanoparticle, (≈19.57 nm) for photocatalysis was prepared via sol-gel method. The fabricated nanomaterial photoelectrochemical characterization was operated using three electrode system with a photoanode as a working electrode, coiled Pt wire as a counter electrode and Hg/Hg2Cl2 as a reference electrode, and 0.5 M Na2SO4 (with pH buffered at 6.75) purged with N2, solution was applied as a supporting electrolyte. The structural and morphological characterizations of the fabricated nanomaterial are carried out using FTIR, XRD, SEM, and EDX techniques, based upon which the mechanistic insights are discussed. SEM analysis suggests that an average size of particle grain size is found to be in the range of 0.5-4 μm. The photocurrent densities of regular TiO2 and LGO-TiO2 towards water splitting reaction under light illumination from xenon lamp were compared and found in reasonable agreement. The work also studied the application of visible light illuminated LGO-TiO2 photoanode photocatalyst to the overall water splitting with a photoconversion efficiency of 18.91% higher than that of bare TiO2 nanoparticles and this suggests that surface functionality, surface topography, porosity and particle size, as well as purity and chemical composition of the prepared sample was successfully functionalized..

Highlights

In the 21st century Lignocellulose biomass industry has become green, possible alternative of fossil resources in order to compensate the increasing trend of world’s demand for petroleum usage in the chemical world
FT-IR spectroscopy was used to analyze the prepared photocatalyst in the range of 4000-400 cm-1
The peaks around at 630 cm-1 assigned to the characterstics vibration of Ti-O-Ti network in the titanium dioxide [11]

Summary

Introduction

In the 21st century Lignocellulose biomass industry has become green, possible alternative of fossil resources in order to compensate the increasing trend of world’s demand for petroleum usage in the chemical world. Maximum attention has been given to TiO2 because of its unique characteristics such as: high photocatalytic activity, Yilkal Dessie Sintayehu: Lignocelluloses Modified TiO2 Nanomaterials as Renewable Photocatalyst for Water Splitting resistance to photo-corrosion, photo-stability, low cost, nontoxicity, and due to its redox capability under ultraviolet (UV) irradiation, i.e., usually the wavelength < 385 nm [7, 8] Such characteristics extends to extensive applications in the area of photovoltaic, sensors, optics, in dye-sensitized and solar cells, for hydrogen gas evolution, self-cleaning surfaces and environmental purification applications [9, 10]. It should be effectively fabricated cotton stalk extracted Lignocellulose (LGO) Titanium oxide (TiO2) nanoparticles via sol-gel in ethanol and investigated their photocatalytic water splitting activities under Visible light irradiation as compared with bare/pure TiO2 with in the phtotoelectrochemical cell (PEC)

Experimental

Results and Discussions

Conclusion