Abstract:
A novel, interface stable and visible light active branched core-shell Bi2S3/Cr-doped ZnO
NRs photo-anode was synthesized using Hydrothermal and SILAR method successively.
The purity, structure of crystals and elemental constitution was investigated using X-ray
diffraction and energy-dispersive X-ray spectroscopy (EDS) techniques respectively. SEM
(Scanning electron microscopy) results illustrates the branched and core-shell nanorods
morphology of all the samples, whether doped or undoped. The study of optical
characteristics of all the photo-anodes was conducted with the aid of UV/vis DRS
(UV/visible diffuse reflectance spectroscopy), Raman spectroscopy and FL (Fluorescence
spectroscopy). The results from FL and UV-vis DRS exhibit the efficient charge separation
and enhanced visible light utilization, respectively. The electrical properties of the photoanodes
were studied using Linear sweep voltammetry (LSV), Chronoamperometry (CA),
Mott-Schottky and Electrochemical impedance spectroscopy (EIS). The optimized sample
10-Bi2S3/6% Cr-doped ZnO NRs shows the highest photo-current density of 2.360 mA cm-
2 at 1.23 V vs RHE and photo-conversion efficiency (%PCE) of 0.565% at 0.39 V vs RHE.
This enhanced photo-electrochemical performance is linked to increased absorption of
visible light by Bi2S3, efficient transfer of electron via the Schottky barrier due to the
suitable band alignment and enhanced interface stability due to Chromium doping.
