“Romanesco broccoli”-like palladium nano-fractals for superior methanol electro-oxidation
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Palladium nanoscale particles possessing distinct planes/facets for fuel cell applications are challenging to construct using simple methods. This work exhibits a facile-solution phase room-temperature synthesis of highly branched and exceptionally ordered 3D Pd nano-fractals (200–300 nm). Using high-resolution atomic imaging, we explain the mechanism of growth and proliferation of facets after twinning. Due to its unique and novel shape, there is an unprecedented 2.025 eV blue shift in d-region of XPS spectra of Pd nano-fractals indicating a phenomenal increase in surface electron density. This is highly favorable for utilizing this promising catalyst for enhanced surface activity. The Pd nano-fractal structures are tested as anodic material, and they show significantly enhanced electrocatalytic activity and superior long-term stability towards methanol oxidation reaction in alkaline media. Thus, low-index enclosed Pd nanostructures could be useful catalysis materials if uniquely shaped and morphologically controlled at nanoscales.
Narinder Singh acknowledges financial support toward his doctorate studies from TEQIP-II and Council of Scientific & Industrial Research (Budget head P-81-101) in the form of senior research fellowship. The authors acknowledge the contribution of SAP (UGC, New Delhi), PURSE (DST, New Delhi), TEQIP-II and TEQIP-III grants to carry out the experimentation at the Institute. The authors thank SAIF/RSIC, Panjab University and Advanced Imaging Centre & Advanced Centre for Materials Science, IIT Kanpur for providing us with instrumentation facilities. The authors also extend their thanks to Dr. Manoj Kumar Nayak, Dr. Pooja Sharma, Dr. S. K. Arora and Mr. Rahul, and CSIO-CSIR for providing cyclic voltammetry facility. The authors express their sincere gratitude to Aman Gupta of M/s Sukhvir Studio, Panjab University Chandigarh for helping in pseudocolouring and Anjali Joshi for contrast resolution imaging.
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Conflict of interest
The authors declare there are no conflicts to declare.
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