Increasing the efficiency of dye-sensitized solar cells by NiCoP/g-C3N4 hybrid composite photoanodes by facile hydrothermal approach

Abstract

In this work, bimetallic phosphide NiCoP was synthesized by a simple hydrothermal method using red phosphorus as the P source. Then, NiCoP was anchored on the surface of g-C3N4 nanosheets via physical grinding followed by calcination. XRD and TEM results suggest that NiCoP has hexagonal crystalline structure with spherical-shaped nanoparticles (25–30 nm), which is uniformly wrapped on the 2D-g-C3N4 nanosheets. The NiCoP/g-C3N4 hybrid composite shows high surface area (105.46 m2/g) and porous nature (11.25 nm) than compared with bare NiCoP (58.51 m2/g and 34.71 nm). UV–Vis spectroscopy shows that the enhancement of absorption spectrum in the UV region with red shift was observed in the composite samples. Furthermore, the energy level difference between NiCoP and g-C3N4 generated a potential barrier that prevented the recombination of the electrons in the NiCoP conduction band with the I3− ions in the electrolyte. The optimal composite photoanode (NCPG-3) exhibits outstanding photoelectric conversion efficiency (PCE) of 11.24%, which exceeds the single NiCoP (4.54%) and is on par with the standard Pt CE (7.12%) under same conditions. This work provides new insights into the utilization of NiCoP/g-C3N4–based photoanode materials for high-performance DSSC–based applications.