Blacking of nano-CdS thin film from gas/liquid interface for enhanced photoelectrochemical performances

Abstract Thin films of CdS nanoparticles were prepared rapidly at gas/liquid interface by dropping Na 2 S ethanol solution onto CdCl 2 solution surface with the help of a surfactant (dodecyl sulfate). The photoelectrochemical cell that comprised of the prepared thin film photoanode of CdS nanoparticles and a Pt cathode generated a photocurrent density as high as 2.8 mA cm −2 at a bias voltage of 0.6 V under visible light illumination of 100 mW cm −2 in an alkaline solution of methanol, which was larger than that in other solutions under investigation. It can be ascribed to methanol-assisted transformation of CdS nanoparticles into black Cd/Cd(OH) 2 /CdS nanocomposites. At 2.8 mA, the decrease of bias voltage reached 2.49 V for hydrogen production with a solar-to-electricity efficiency of 4.65%.