Abstract for Poster
Efficient and Stable Band gap engineering of BiFeO3 for hydrogen production through photoelectrochemical splitting of water
Amit Srivastava1,2,*, Alok K Vishwakarma3 and O.N.Srivastava3
1.Department of Physics,TDPG College,VBS Purvanchal University-Jaunpur 222001.India
2.Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306,USA
3.Department of Physics, Institute of Science, Banaras Hindu University, Varanasi-221005,India
* Email:amitrac@gmail.com
The present manuscript describes the synthesis and band gap engineering of  Gd and Co doped BiFeO3(BFO) nanoceramics by sol-gel method and hydrogen  production through photoelectrochemical splitting of water, using it as a photoanode. X-ray diffraction (XRD) patterns indicate the formation of pure phase of BiFeO3 and its variants. The Surface morphologies and particle sizes of different compositions have been investigated through scanning electron microscope (SEM).The co-doping leads to the band gap engineering of BiFeO3 with the band gap varying from 2.23 eV to 1.77 eV. The band gap engineering coupled with UV-Vis spectroscopy has been used to achieve optimal materials to be studied further.The substantial lowering in band gap of the doped BFO is attributed to the deformation produced  in Fe-O octahedron geometry as well as rearrangement in its molecular orbitals.The as synthesized BFO as well as its doped variants have been used as photoanodes for hydrogen production through PEC splitting of water. The optimum material Bi1-xGdxFe1-yCoyO3(x=0.1 and y=0.25) with a band gap of 1.77 eV has been used as photoanode having PEC configuration of 1mol/L NaOH as an electrolyte solution and metal Pt as cathode using 1.5AM UV-Vis illumination. It provides a photocurrent density of 2.03mA/cm2 and hydrogen  production  rate of  74.57 mmol cm-2h-1.The maximum photoconversion efficiency has been found to be 2.29% which is significantly higher than that of prestine BFO having 0.76%. This noteworthy enhancement in the photoelectrochemical properties is ascribed to narrowing the bandgap which eventually improves the solar spectral response and allows the absorption of higher density of photons. 
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