Herein, we report that an efficient nanohybrid material consists of Cd-doped ZnS nanocrystals (NCs), merocyanine and fullerene (C60-pyrrolidine tris acid). Cd-ZnS NCs serve as a substrate for supramolecular complexation between merocyanine 540 and fullerenes. The impact of grafting and co-grafting of dyes on the NCs surface was checked by Fourier transform infrared (FTIR), photoluminescence and ultraviolet–visible (UV–Vis) spectroscopic studies. Cd-doped ZnS NCs were synthesized by wet chemical approach and described by powdered X-ray diffraction, UV–Vis spectroscopy, field emission scanning electron microscopy and transmission electron microscopy. The grafted and cografted NCs were then used as an active blend in hybrid solar cells. The hybrid solar cell of grafted material blend (Cd- ZnS-MC540) shows the maximum short circuit current density 4.60 mA cm$^{–2}$ and power conversion efficiency of 0.83%. The open circuit voltage, fill factors and cell conversion efficiency of all photovoltaic devices based on co-grafted Cd-doped ZnS NCs and P3HT decreases with the increase in concentration of donor and acceptor species. We note that by cografting, dye/dye interaction is replaced by dye/fullerene interaction but unfortunately co-grafting may have led to the formation of big clusters. Hence, the lack of morphological homogeneity may be held responsible for the weak performance of the solar cells.

Photoelectrochemical (PEC) water splitting is an emerging way for the production of H$_2$, which has the ability to reduce the dependence on fossil fuels for the power generation and provide an ecologically safe storage of solarenergy. Fabrication of photoelectrode is one of the major challenges to make PEC water splitting more effective and efficiently sustainable. In this article, we have focussed on the studies of antimony (Sb)-incorporated ZnO photoelectrodes and their evident effects in boosting the PEC water splitting activities using different concentrations of Sb incorporated on fluorine-doped tin oxide (FTO) via aerosol-assisted chemical vapour deposition method (AACVD). The as-deposited photoelectrodes were characterized by using different techniques and were applied for the water splitting. The incorporated thin films exhibited better light absorbance in the visible range, probably because of the generation of extra energy levels through metal incorporation. An enhanced PEC water splitting performance was observed by Sb-incorporated ZnO photoelectrodes as compared to pure ZnO. More specifically, 15% Sb-incorporated ZnO attained a photocurrent density of 0.99 mA cm$^{-2}$ at 0.85 V vs. Ag/AgCl and maximum photo-stability that is quite greater as compared to pure ZnO (0.19 mA cm$^{-2}$). This improvement was stated by the reduced bandgap and multifaceted morphological aspects of Sb incorporated ZnO. In the production of simple and low-cost synthetic methods and effective electrode materials for PEC water splitting applications, these results are proved to be very helpful.