Photo-electrochemical Water Splitting Behaviour of Rare Earth Metal Oxide Based Phthalocyanines Nanocomposites

Here, we describe the photo-electrochemical water splitting behaviour of Gd2O3 pc (GdPc) and La2O3 pc (LaPc), two phthalocyanines (pc) based on rare earth oxides. The hydrothermal technique was utilised to synthesise the GdPc and LaPc. Using X-ray diffraction (XRD) analysis, the phase purity and crystallinity of LaPc and GdPc were investigated. The findings show that GdPc likewise has a high crystallinity with a cubic structure, while LaPc has a high crystallinity with a hexagonal structure. Field emission scanning electron microscopy (FESEM) was used to evaluate surface morphological findings. It is observed that organic phthalocyanine aggregates with rare earth oxide nanoparticles. Using UV-Vis spectroscopy, the light absorption characteristics of LaPc and GdPc were examined. The LaPc exhibited widespread absorption between 500 and 800 nm. GdPc similarly showed large absorption peaks between 500 and 800 nm and absorption peaks at 430 nm. In both dark and light circumstances, photo-electrochemical water splitting in 1M Na2S electrolyte was carried out using the LaPc and GdPc as photo electrocatalysts. The LaPc photoelectrode demonstrated a current density of approximately 3.5 mA/cm2 at 0.8 V (vs. Ag/AgCl) in light illumination and approximately 3.0 mA/cm2 in the dark, according to Linear Sweep Voltammetry (LSV) tests. In a similar vein, under light illumination the GdPc photoelectrode had a current density of approximately 9.0 mA/cm2 at 0.8 V (vs. Ag/AgCl) as opposed to ~7.5 mA/cm2 in the dark. The LaPc photoelectrode demonstrated a greater current density of approximately 7.5 mA/cm2 at 0.8 V (vs. Ag/AgCl) under light illumination as opposed to approximately 7.0 mA/cm2 in the dark, according to the Chronoamperometric (CA) research observations. In a similar vein, the GdPc photoelectrode showed a current density of about 11.5 mA/cm2 in the dark and ~11.5 mA/cm2 at 0.8 V (vs. Ag/AgCl) in the light. According to the PEC data, GdPc showed greater water splitting activity than LaPc.