Synthesis of Co3O4 electrodes by electrochemical deposition for water splitting reaction
Authors:   University of Science, VNU-HCM, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Viet Nam, La Ha Phuong Phan ,   Viet Nam National University Ho Chi Minh City, Thu Duc City, Ho Chi Minh City, Viet Nam, Tran Phat Hong Nghia ,   University of Science, VNU-HCM, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Viet Nam; Viet Nam National University Ho Chi Minh City, Thu Duc City, Ho Chi Minh City, Viet Nam, Bui Thach Khac ,   Advanced Materials and Applications Research Group (AMA), HUTECH University, 475A Dien Bien Phu Street, Binh Thanh District, Ho Chi Minh City 700000, Viet Nam, Le Giang Thuy Thanh ,   University of Science, VNU-HCM, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Viet Nam; Viet Nam National University Ho Chi Minh City, Thu Duc City, Ho Chi Minh City, Viet Nam, Nguyen Hao Duc ,   University of Science, VNU-HCM, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Viet Nam; Viet Nam National University Ho Chi Minh City, Thu Duc City, Ho Chi Minh City, Viet Nam, Pham Viet Van ,   Advanced Materials and Applications Research Group (AMA), HUTECH University, 475A Dien Bien Phu Street, Binh Thanh District, Ho Chi Minh City 700000, Viet Nam
Published: April 2024

Introduction: The use of Ni foam substrates for the growth of catalysts is a common practice in electrochemical water splitting reactions, although their stability in some electrolytes can be problematic, hindering the scalability of synthesis. This study aims to explore alternative substrates for catalyst growth, focusing on cobalt oxide (Co3O4) due to its potential in enhancing electrochemical water splitting efficiency.

Methods: Cobalt oxide (Co3O4) was synthesized on various conductive substrates including fluorine-doped tin oxide (FTO), indium-doped tin oxide (ITO), and carbon cloth (CC), employing electrochemical deposition techniques. The morphological and crystalline properties of the Co3O4 coatings on these substrates were characterized and analyzed to understand their influence on the catalyst's performance in water splitting reactions.

Results: The electrochemical deposition resulted in a more condensed coverage of Co3O4 on the CC substrate, attributed to the crystal's oriented aggregation. The crystallization and lattice development of Co3O4 varied significantly across different substrates, exhibiting high crystallization on FTO and ITO substrates but poorer crystallization on the CC substrate. Notably, the Co3O4/CC electrode demonstrated superior performance in hydrogen evolution reaction, achieving the lowest overpotential of -382 mV at a current density of 10 mA cm-2.

Conclusion: The findings suggest that carbon cloth (CC) presents a promising alternative to Ni foam substrates for the growth of Co3O4 catalysts in electrochemical water splitting applications. The enhanced performance of Co3O4/CC electrodes, particularly in terms of overpotential and crystallization behavior, highlights the potential of using CC substrates to improve the efficiency and scalability of water splitting reactions for sustainable hydrogen production.