RSC Advances Blog

Graphene is certainly a hot topic in research right now. A quick look down this very blog shows that it featured in no fewer than seven of the top ten accessed articles in RSC Advances during 2012 (including all of the top three)!

This versatile material appears as oxides, composites, quantum dots, nanomaterials and foams and it has been investigated for uses in photocatalysis, energy, environmental applications and more.

Now researchers in India and China have been investigating graphene supported platinum catalysts for fuel cells.

Sreekuttan M. Unni and colleagues report the first synthesis of a 3D self-assembled single crystalline platinum nanostructure directly on a graphene surface without structural directing agents, by using a slow reduction method. In their paper, they show superior electrocatalytic activity towards the oxygen reduction reaction, a crucial reaction for hydrogen-fuelled polymer electrolyte fuel cells. They show that their material also has less vulnerability to strong hydroxyl adsorption and a higher limiting current density than other graphene supported platinum or commercial platinum-on-carbon catalysts.

Meanwhile Jian Zhao and colleagues have published about their supercritical fluid route for preparing graphene-supported platinum-ruthenium nanoparticles in an effective, simple, low temperature and environmentally benign way. They used supercritical CO₂ to uniformly distribute ultrafine PtRu nanoparticles with an average size of 2.87 nm on the surfaces of functionalized graphene sheets. They found considerably improved catalytic activity and stability for methanol oxidation from their supported nanoparticles because of the uniform distribution. Their supercritical approach may have promise for development of direct methanol fuel cells.

Find out more about this research in RSC Advances:

3-Dimensionally self-assembled single crystalline platinum nanostructures on few-layer graphene as an efficient oxygen reduction electrocatalyst, Sreekuttan M. Unni, Vijayamohanan K. Pillai and Sreekumar Kurungot, RSC Adv., 2013, 3, 6913-6921

Methanol electrocatalytic oxidation on highly dispersed platinum–ruthenium/graphene catalysts prepared in supercritical carbon dioxide–methanol solution, Jian Zhao, Lin Zhang, Hao Xue, Zhaobo Wang and Haiqing Hu, RSC Adv., 2012, 2, 9651–9659

Supercapacitors, also known as electrochemical capacitors, are used as highly reliable energy storage devices with the advantage of rapid charge and discharge compared to batteries. However to further expand their use it is necessary to improve their performance in other areas including energy density.

Ruthenium oxide is the material widely used for supercapacitor electrodes. Its use is reviewed by Wentao Deng and colleagues in China and the UK, in a comprehensive overview of the state-of-the-art in this area.

Work has not stopped on improving the performance of these highly promising devices – far from it. Just to take a couple of examples, Sho Makino and colleagues from Japan have used nanostructured ruthenium oxide in an aqueous hybrid supercapacitor with a specific energy comparable to modern rechargeable batteries, opening the possibility of using these materials in a post-lithium ion battery technology. Meanwhile Beena Balan and colleagues from India have looked at decorating carbon nanotubes with ruthenium oxide to produce a ternary electrode material to increase the specific capacitance by 103%, with enhanced rate and excellent electrochemical stability.

Read more about this valuable research in RSC Advances – free to access for 4 weeks:

Electrochemical capacitors utilising transition metal oxides: an update of recent developments, Wentao Deng, Xiaobo Ji, Qiyuan Chen and Craig E. Banks, RSC Adv., 2011, 1, 1171

4 V class aqueous hybrid electrochemical capacitor with battery-like capacity,Sho Makino, Yuto Shinohara, Takayuki Ban, Wataru Shimizu, Keita Takahashi, Nobuyuki Imanishib and Wataru Sugimoto, RSC Adv., 2012, 2, 12144

Carbon nanofiber–RuO2–poly(benzimidazole) ternary hybrids for improved supercapacitor performance, Beena K Balan, Harshal D Chaudhari, Ulhas K Kharul and Sreekumar Kurungot, RSC Adv., 2013, 3, 2428