Electrochemical synthesis of a novel porous gold-curcumin nanocomposite for energy generation from alcohols

Identifying the Issue

Alcohol based fuel cell require a catalyst that efficiently breaks down alcohol molecules at the electrode surface for generating energy. The catalyst must also be environmentally benign, have high energy efficiency, and operate at ambient temperatures.

Objective of the Research

• Synthesize gold-based nanocomposites using simple organic molecules
• Adopt a cost-effective and energy efficient electrochemical synthesis yielding small size gold nanoparticles exhibiting excellent catalytic activity
• Provide an alternate to earlier reported metal-polymer composites serving as catalysts for oxidation of alcohols

Who should read this?

Anyone in industry/academia, working directly or indirectly on synthesis of efficient catalysts to be used for various electrochemical applications such as alcohol oxidation, sensors, hydrogen evolution reaction or oxygen evolution/reduction reactions.

Solution

Gold nanoparticles (AuNPs) possess tuneable size- and shape-dependent properties that are ideal for catalytic properties for many applications. However, the challenge lies in the synthesis of highly stable and ultra-small NPs. We report an energy-efficient galvanostatic route to engineer gold-curcumin (Au-CM) nanocomposites constituting small-sized (~2 nm) AuNPs enveloped by a porous network of curcumin. During electrolytic deposition, the in situ formed Au-CM complexes are the key for the low current involved in our electrosynthesis, which ultimately deposits as CM-enveloped AuNPs at the cathode (Au-CM/GCE).

The DFT study also presented high binding energy (18.76 eV) of Au-CM complex in the solvent phase. The Au-CM/GCE nanocomposite exhibited excellent stability (~200 cycles), facile electron transfer ability, catalytic activity, and low Arrhenius energy of 42 and 45 kJ mol−1, respectively, towards electrooxidation of EtOH and MeOH in alkaline medium. The oxidation kinetics are comparable to those of the best gold-polymer composites. This study points the way for one-pot green synthesis of other engineered electrocatalysts for different applications.

Key Features and Benefits

• Usage of very low current (100-1000 times lower than earlier reported values) for direct synthesis of gold nanoparticles using simple, natural organic molecules
• Electrodeposition of small-sized gold nanoparticles (~2 nm) embedded in a porous curcumin network
• The synthesised catalyst is highly stable during repeated use towards electro-oxidation of alcohols
• The reported gold-curcumin catalyst exhibits low activation energy for oxidation of alcohols

Impact

The research work presents an efficient and stable gold based electrocatalyst that can be used in design of ethanol based fuel cells. The reported catalyst serves as a suitable alternate to metal-polymer based catalysts

Team

• Sai Prasad Nayak, Department of Chemistry, Brindavan campus, SSSIHL
• Dr. Lakshman K. Ventrapragada, Department of Physics and Astronomy, Clemson Nanomaterials Institute, Clemson University, USA
• Dr. Sai Sathish Ramamurthy, STAR Laboratory, Department of Chemistry, SSSIHL
• Dr. J. K. Kiran Kumar, Department of Chemistry, Brindavan campus, SSSIHL
• Prof. Apparao M. Rao, Bowen Professor of Physics, Department of Physics and Astronomy; Director, Clemson Nanomaterials Institute, Clemson University, USA

Paper Published in: Nano Energy (The impact factor for the journal is in excess of 17)

Title: Green synthesis of a novel porous gold-curcumin nanocomposite for super-efficient alcohol oxidation

Read Paper Here: https://doi.org/10.1016/j.nanoen.2022.106966