Hydrogen, due to its high energy density (over 4 times per kg energy capacity compared to that of petrol or diesel) and clean-burning characteristics (water being the sole byproduct) is an ideal fuel. It can be obtained by simply electrolyzing water. However, hydrogen production on a large scale from water splitting is mainly constrained due to its high overpotential (300-600 mV) requirements, sluggish kinetics, low efficiency, and instability of electrode materials. Pt and IrO2/RuO2 based materials are the benchmark electrocatalyst that can potentially catalyze both the HER and OER reactions at low overpotentials. But, their poor stability, low abundance, and high cost have strongly discouraged their widespread commercial interest. Recently, alternative materials that are cheap, abundant, and easy to process have also piqued lots of interest. These include metal/metal alloy, various oxides, chalcogenides i.e., metal-sulfides, phosphides, and perovskites among others. Almost all these heterogeneous catalysts require some sorts of binders (Nafion/polymers) to translate these to respective electrodes which seriously impact their performance. This performance deterioration can be linked to the blockage of some of the active sites of the catalyst. In addition, self-supported catalysts realized by directly depositing metal nanoparticles on cheap and stable supports without any binder or additive can deliver cheap, durable, and highly efficient catalysts. The self-supported electrocatalyst is preferable for electrolysis as they possess the following merits. First, the in-situ development of the active phase on the current collector (substrate) evades the post coating process, polymeric binder, and electronic conducting agent which decreases the cost and simplifies the complete electrode fabrication process. Second, the conducting substrate facilitates the homogenous and high loading of guest materials due to direct involvement in the nucleation process. Third, this approach offers a strong electronic and ionic contact between the substrate and transition metals without a binder and conducting agent. This tight integration increases the resistance of nanomaterials against chemical transformation and enhances the rate of charge transfer at the interfacial boundary<b>.</b> Thus, the development of cheap, self-supported (binder-free) and scalable electrode materials that can efficiently replace the existing noble metal-based materials is highly desirable.

Development of self-supported transition metal based electrocatalyst for water splitting as a sustainable source of energy

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.