Prof. Vivek Polshettiwar’s NANOCAT group works on the development of novel nanomaterials for catalysis, solar energy harvesting, and CO₂ capture-conversion to tackle “climate change”. They have developed next-generation nanocatalysts via the morphological control of nanomaterials, dendritic fibrous nanosilica (DFNS). The uniqueness of DFNS is its high surface area is produced by its fibrous structure instead of the formation of pores, making the large surface area easily accessible (Nature Protocol. 2019, 14, 2177-2204, Indian Patent Appl. 201621004089). DFNS is now being used for various applications, such as catalysis, photocatalysis, CO₂ capture-conversion, RNA extraction from viruses, energy harvesting & storage, drug delivery, etc.

By using the techniques of nanotechnology, they have transformed DFNS based yellow gold to black gold by changing the size and gaps between gold nanoparticles. Similar to the real trees, the developed black gold acts like an artificial tree that uses CO₂, sunlight, and water to produce fuel. This work on “Black (nano)Gold” is one-of-its-kind and a way forward to develop “Artificial Trees” which captures and converts CO₂ to fuel and useful chemicals and CO₂ may then become our main source of clean energy (Chemical Science, 2019, 10, 6694-6603, Indian Patent Appl. 202021001441).

His group also showed that “Defects in DFNS” convert CO₂ to fuel with excellent productivity and selectivity (an entirely new concept in the field). Neither metal nor complex organic ligands were required, and the defect alone acted as catalytic sites. Surprisingly, the catalytic activity for methane production increased significantly after every regeneration cycle, which they explained by a detailed mechanistic study. (Proc. Natl. Acad. Sci. U.S.A 2020, 117, 6383-6390, Indian Patent Appl. 202021001440).

They also developed “Acidic Amorphous Aluminosilicates (AAS)”, which possess Brønsted acidic sites like in zeolites and porous textural properties and were used for catalysis, plastic degradation and CO₂ to fuel conversion. Conventional and DNP-enhanced SS NMR provided a molecular-level understanding of these materials (Nature Commun. 2020, 11, 3828, Indian Patent Appl. 202021040554.).

Their work on “Capturing CO₂ before its Release” using lithium silicates nanosheets with excellent capture capacity, kinetics and stability can provide a novel path to capture CO₂ inside the reactor itself and stopping their release to the environment (Chem. Sci., 2021, 12, 4825, Indian Patent Appl. 202021008717).

Recently they showed that "Bubble the Air in Water with a pinch of Magnesium and you will get Fuel (methane, hydrogen) and green cement". No heat, electricity, or light energy was required; simply the use of water and magnesium in just a few minutes. This protocol can even be used for hydrogen production (940 liter per kg of Mg), which is nearly 420 times more than hydrogen produced by the reaction of Mg with water alone (2.24 liter per kg of Mg). (Chem. Sci., 2021, 12, 5774, PCT App. No. PCT/IN2020/50458).

Prof. Polshettiwar’s group has developed their own research field on “Fibrous Nanosilica based Catalysis” and more than 150 groups worldwide are now working in the field that Vivek started. This is one of the very few examples of such widespread use of material invented by Indian researchers. In addition to fundamental research on DFNS, group is also trying to commercialize it with the help of industries to create a real societal impact of his research; a step towards “Atmanirbhar Bharat”.

Nanocat group’s work is recently summarized in Acc. Chem. Res.  2022, 55, 1395–1410.

More details about the group’s research is at https://www.nanocat.co.in/

• Dendritic Fibrous Nano-Silica (DFNS): Discovery, Synthesis, Formation Mechanism, Catalysis, and CO2 Capture-Conversion. Vivek Polshettiwar* ACS Accounts of Chemical Research, 2022, 55, 1395–1410.
• Direct CO2 Conversion to Fuels on Magnesium Nanoparticles at Ambient Conditions Simply Using Water. S. A. Rawool, R. Belgamwar, R. Jana, A. Maity, A. Bhumla, N. Yigit, A. Datta, G. Rupprechter, Vivek Polshettiwar* Chemical Science, 2021, 12, 5774-5786.
• Lithium Silicates Nanosheets with Excellent Capture Capacity and Kinetics with Unprecedented Stability for High-Temperature CO2 Capture. Rajesh Belgamwar, Ayan Maity, Tisita Das, Sudip Chakraborty, C. P. Vinod, Vivek Polshettiwar* Chemical Science, 2021, 12, 4825-4835.
• Catalytic Nanosponges of Acidic Aluminosilicates for Plastic Degradation and CO2 to Fuel Conversion. Ayan Maity, Sachin Chaudhari, Jeremy J. Titman, Vivek Polshettiwar* Nature Communications 2020, 11, Article number: 3828.
• Defects in Nanosilica Catalytically Convert CO2 to Methane without Any Metal and Ligand. Amit K. Mishra, Rajesh Belgamwar, Rajkumar Jana, Ayan Datta, and Vivek Polshettiwar* Proc. Natl. Acad. Sci. U.S.A 2020, 117, 6383-6390.
• Plasmonic Colloidosomes of Black Gold for Solar Energy Harvesting and Hotspots Directed Catalysis for CO2 to Fuel Conversion. M. Dhiman, A. Maity, A, Das, R. Belgamwar, B. Chalke, Y. Lee, Kyunjong Sim, Jwa-Min Nam and Vivek Polshettiwar* Chemical Science, 2019, 10, 6594-6603.
• Facile Synthesis Protocol to Tune Size, Textural Properties & Fiber Density of Dendritic Fibrous Nanosilica (DFNS): Applications in Catalysis and CO2 Capture. A. Maity, R. Belgamwar, Vivek Polshettiwar*, Nature Protocol, 2019, 14, 2177-2204.
• Scalable and Sustainable Synthesis of Size Controlled Monodisperse DFNS Quantified by E-Factor. Ayan Maity, Vivek Polshettiwar,* ACS Applied Nanomaterials, 2018, 1, 3636-3643.
• Unraveling the Formation Mechanism of Dendritic Fibrous Nanosilica. Ayan Maity, A. Das, D. Sen, S. Mazumder, Vivek Polshettiwar*, Langmuir, 2017, 33, 13774-13782.
• Atomic Layer Deposited (ALD) TiO2 on Fibrous Nano-Silica (KCC-1) for Photocatalysis: Nanoparticle Formation and Size Quantization Effect. Rustam Singh, Rudheer Bapat, L. Quen, H. Feng,* and Vivek Polshettiwar* ACS Catalysis 2016, 6, 2770−2784.
• Design of CO2 Sorbents using Functionalized Fibrous Nanosilica (KCC-1): Insights into the Effect of the Silica Morphology (KCC-1 vs MCM-41). Baljeet Singh and Vivek Polshettiwar* J. Mat. Chem. A. 2016, 4, 7005-7019.
• SBA-15-Oxynitrides as a Solid-Base Catalyst: Effect of Nitridation Temperature on Catalytic Activity. Baljeet Singh, K. R. Mote, C. S. Gopinath, P. K. Madhu,* Vivek Polshettiwar*, Angew. Chem. Int. Ed. 2015, 54, 5985-5989.
• Insights Into the Catalytic Activity of Nitridated Fibrous Silica (KCC-1) Nanocatalysts from 15N and 29Si NMR Enhanced by Dynamic Nuclear Polarization. A. S. L. Thankamony, C. Lion, F. Pourpoint, B. Singh, A. J. Perez Linde, D. Carnevale, G. Bodenhausen, H. Vezin, Olivier Lafon,* Vivek Polshettiwar* Angew. Chem. Int. Ed. 2015, 54, 2190-2193.