Photoelectrochemical(PEC) water splitting is considered one of the most promising technologies for clean hydrogen generation from solar energy. IrOx electrocatalysts have been widely used for water electrolysis due to the strong acidic conditions and slow kinetics in Oxygen Evolution Reaction (OER) at the anode. Given the high cost and lack of Ir on the earth, reducing Iridium content for OER is a crucial aspect towards the commercialization of PEC water splitting. In this research, we have synthesized and investigated low-loading precious metal catalysts using iridium and transition metals with different ratios. Additionally, we modified the surface of the electrode using conductive epoxy and sanded graphite sheets to improve limited stability via corrosion in the strong acidic electrolyte and detachment of the catalyst. The OER activity of low-loading precious metal catalysts increased as the thickness of the graphite decreased and defected. The Ir-based bimetallic nanoparticles showed enhanced OER activity compared to Ir-only. This research provides valuable insights into the effective utilization of precious metals and making efficient structure for OER, which will be crucial in improving hydrogen production through water splitting and making the process more economical.