Crystal Growth Behavior and Photoelectrochemical Water Purification Performance of Cu2O Photocathodes Controlled by Electrodeposition Voltage

초록

Control of the microstructure of photocathodes is a key factor governing the efficiency of organic pollutant degradation in photoelectrochemical (PEC) water purification systems. Cu2O photocathodes were prepared via electrodeposition, and the relationship between applied deposition voltage, crystal structure, and PEC water purification performance was investigated. To promote preferential growth along the (111) crystallographic direction, the electrolyte pH was maintained at 11, and the potential window for stable Cu2O deposition was determined to be 0.3 to 0.7 V by linear sweep voltammetry. The structural properties of the electrodeposited Cu2O films were characterized by X-ray diffraction and scanning electron microscopy, while their PEC performance was evaluated using methyl orange as a model organic pollutant. The Cu2O photocathode deposited at 0.5 V exhibited a pronounced (111) preferred orientation, enlarged grain size, and a uniform film morphology, resulting in the highest photocurrent density and excellent operational stability under simulated 1-sun illumination. These findings demonstrate that precise control of electrodeposition voltage is crucial for optimizing the PEC performance of Cu O photocathodes and highlight their potential for environmentally friendly water purification applications.

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