CdS-sensitized TiO2 nanocorals: hydrothermal synthesis, characterization, application

Cadmium sulfide (CdS) nanoparticle-sensitized titanium oxide nanocorals (TNC) were synthesized using a two-step deposition process. The TiO2 nanocorals were grown on the conducting glass substrates (FTO) using A hydrothermal process and CdS nanoparticles were loaded on TNC using successive ionic layer adsorption and reaction (SILAR) method. The TiO2, CdS and TiO2-CdS samples were characterized by optical absorption, X-ray diffraction (XRD), FT-Raman, FT-IR, scanning electron microscopy (SEM) and contact angle. Further, their photoelectrochemical (PEC) performance was tested in NaOH, Na2S-NaOH-S and Na2S electrolytes, respectively. When CdS nanoparticles are coated on TNCs, the optical absorption is found to be enhanced and band edge is red-shifted towards visible region. The TiO2-CdS sample exhibits improved photoelectrochemical (PEC) performance with maximum short circuit current of (Jsc ) 1.04 mA cm−2. After applying these TiO2-CdS electrodes in photovoltaic cells, the photocurrent was found to be enhanced by 2.7 and 32.5 times, as compared with those of bare CdS and TiO2 nanocorals films electrodes respectively. Also, the power conversion efficiency of TiO2-CdS electrodes is 0.72%, which is enhanced by about 16 and 29 times for TiO2, CdS samples.