Cu–Cu2O Nanorod-CdS heterostructures on carbon cloth for efficient photoelectrocatalytic water splitting

Photoelectrochemical (PEC) water splitting represents a critical pathway toward sustainable hydrogen production, addressing global energy challenges. This study presents an innovative strategy to fabricate a highly efficient photoanode by integrating n-type CdS with p-type Cu–Cu₂O nanorods on a flexible carbon cloth substrate using electrodeposition techniques. This CdS/Cu–Cu₂O nanocomposite establishes a p-n heterojunction at the carbon cloth interface, significantly enhancing overall PEC performance. Under LED illumination (∼80 mW/cm²), the optimized photoanode achieved an impressive photocurrent density of 8.7 mA/cm² at 1.23 V versus the reversible hydrogen electrode (RHE), representing a 2.7-fold improvement over the unmodified CdS photoanode. The observed enhancement in photoelectrochemical (PEC) performance can be attributed to the deliberate and meticulous design of the CdS/Cu–Cu₂O interface, which facilitates superior charge carrier dynamics. This improvement arises from the synergistic combination of surface engineering and structural optimization, both of which significantly influence the efficiency of charge separation and transfer. Importantly, precise control over surface morphology and defect density is pivotal in optimizing the photoelectrode’s functional properties, ensuring superior stability and performance. Furthermore, the CdS/Cu–Cu₂O photoanode demonstrated exceptional photostability, maintaining a steady photocurrent density of 8.7 mA/cm² over 10 h of continuous operation. This work underscores the pivotal role of tailored surface and interfacial engineering of carbon cloth substrates in enhancing both the efficiency and the long-term durability of photoelectrochemical (PEC) systems.