Interface-engineered N-doped carbon dot/CdSe nanoconjugates as efficient Bi-functional electrocatalysts in alkaline...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Electrochemical water splitting is crucial for sustainable energy but requires efficient and affordable electrocatalysts.
• Sluggish kinetics of water oxidation necessitate the development of high-performance catalysts.

Purpose of the Study:

• To design and demonstrate a cost-effective carbon quantum dots/cadmium selenide (CQDs/CdSe) nanocomposite for integrated hydrogen evolution reaction (HER) and oxygen evolution reaction (OER).
• To investigate the catalytic performance and stability of the CQDs/CdSe nanocomposite for sustainable hydrogen generation.

Main Methods:

• Hydrothermal synthesis of CQDs/CdSe nanocomposite.
• Electrochemical characterization including overpotential and Tafel slope measurements for HER and OER.
• Fabrication and testing of a two-electrode water electrolysis device using the nanocomposite as both anode and cathode.

Main Results:

• The CQDs/CdSe nanocomposite exhibited low overpotentials of 95 mV for HER and 170 mV for OER at 10 mA cm⁻².
• Tafel slopes of 43 mV dec⁻¹ (HER) and 63 mV dec⁻¹ (OER) indicate efficient reaction kinetics.
• The catalyst demonstrated excellent stability over 50 hours at 50 mA cm⁻².
• A proof-of-concept device achieved 10 mA cm⁻² at 1.77 V, showcasing real-time hydrogen and oxygen evolution.

Conclusions:

• The CQDs/CdSe nanocomposite is a highly efficient and stable electrocatalyst for integrated HER and OER.
• This work highlights the potential of CQD-based hybrid nanostructures as scalable and earth-abundant electrocatalysts for sustainable hydrogen production.