Photoelectrochemical solar water splitting using electrospun TiO2 nanofibers

TiO2 nano-fibrous films of thicknesses ranging from 0.17 to 3.24 μm were prepared on an indium-doped tin oxide substrate using an electrospinning technique for which the spinning time was varied from 5 to 60 min. The structural and morphological aspects were studied by means of XRD, Raman, and SEM analyses. The photoelectrochemical (PEC) properties of the films were tested by performing current-potential measurements. The optimal PEC performance was explored by varying the experimental conditions, specifically, the spinning time (5-60 min) and the annealing temperature (300, 500, and 700 °C). A comparison of the PEC performance of all the NF film thicknesses (0.17, 0.31, 1.53, 2.16, 4.67, and 7.53 μm) revealed that a thickness of 4.67 μm, that is, a film formed by electrospinning over a duration of 45 min, exhibited the optimum level of PEC performance. This film generated a photocurrent of around 150 μA/cm2, which was larger than the PEC values produced by the other films. The PEC performance of the 7.53-μm TiO2 NF film (produced by coating for 60 min) was found to be inferior to that of all the other thicknesses.