Energy and environment are two of our critical societal challenges. The use of hybrid nanomaterials to harvest solar energy as well as capture and convert CO2 seems to be the best way combat climate change. We recently reported the synthesis of a new class of dendritic fibrous nano-silica (DFNS). Fibrous morphology observed in these nanospheres has not been seen before in silica materials. Uniqueness of DFNS is, its high surface area is by virtue of its fibrous structure instead of pores (unlike MCM-41 and SBA-15 silicas), and hence easily accessible. More than 100 groups worldwide is now using our patented DFNS for various applications such as catalysis, solar-energy harvesting, energy storage, self-cleaning antireflective coatings, surface plasmon resonance-based ultrasensitive sensors, CO2 capture, and biomedical applications.1d We showed successful utilization of DFNS for range of important catalytic applications such as metathesis, hydrogenolysis, oxidation, hydrogenation, coupling reactions etc. as well as for CO2 capture. We have also developed a new method of fabricating active photocatalysts by TiO2 coating of DFNS and plasmonic black gold.
In the nano-catalysis (NanoCat) laboratory, we are designing and synthesizing various nano-materials (silica, metal oxides, metals, etc) with specific shapes, sizes and morphologies and then evaluating their use as a nano-catalysts for the development of sustainable protocols for various processes like photocatalysis, CO2 capture and conversion to fine chemicals, environmental remediation as well as C-H activation, C-C coupling, oxidation, metathesis, hydrogenolysis, hydrogenation reactions.
A guiding hypothesis is that catalytic efficiency (activity, kinetics, selectivity and stability) can be controlled by tuning the morphology of nanomaterials/nanocatalysts.
The work of our group in the realms of "Black Gold" and defect chemistry represents a quintessential example of how fundamental science can drive innovation in applied research. The detailed exploration of plasmonic photocatalysis and defect engineering offers new perspectives on material design, and catalysis, paving the way for future research that continues to explore the potential of nanomaterials in solving environmental and energy challenges.
Dendritic Fibrous nanosilica (DFNS):
Polshettiwar’s team invented novel DFNS, which stands out for its high surface area facilitated by its fibrous structure. This Indian-invented material has garnered global attention, with over 150 reputable groups worldwide exploring its applications across various fields. This work has expanded the boundaries of material science, offering profound insights into the design and synthesis of nanomaterials with specific morphological controls. This has not only enriched our understanding of nanoscale material properties but also established DFNS as a foundational material for further scientific inquiry in nanochemistry and material science.
[Selected publications: Nature Protocol, 2019, 14, 2177; Acc. Chem. Res. 2022, 55, 1395; Angew. Chem. Int. Ed. 2015, 54, 2190; Angew. Chem. Int. Ed. 2015, 54, 5985; Langmuir 2017, 33, 13774]
In the nano-catalysis (NanoCat) laboratory, we are designing and synthesizing various nano-materials (silica, metal oxides, metals, etc) with specific shapes, sizes and morphologies and then evaluating their use as a nano-catalysts for the development of sustainable protocols for various processes like photocatalysis, CO2 capture and conversion to fine chemicals, environmental remediation as well as C-H activation, C-C coupling, oxidation, metathesis, hydrogenolysis, hydrogenation reactions.
A guiding hypothesis is that catalytic efficiency (activity, kinetics, selectivity and stability) can be controlled by tuning the morphology of nanomaterials/nanocatalysts.
The work of our group in the realms of "Black Gold" and defect chemistry represents a quintessential example of how fundamental science can drive innovation in applied research. The detailed exploration of plasmonic photocatalysis and defect engineering offers new perspectives on material design, and catalysis, paving the way for future research that continues to explore the potential of nanomaterials in solving environmental and energy challenges.
Dendritic Fibrous nanosilica (DFNS):
Polshettiwar’s team invented novel DFNS, which stands out for its high surface area facilitated by its fibrous structure. This Indian-invented material has garnered global attention, with over 150 reputable groups worldwide exploring its applications across various fields. This work has expanded the boundaries of material science, offering profound insights into the design and synthesis of nanomaterials with specific morphological controls. This has not only enriched our understanding of nanoscale material properties but also established DFNS as a foundational material for further scientific inquiry in nanochemistry and material science.
[Selected publications: Nature Protocol, 2019, 14, 2177; Acc. Chem. Res. 2022, 55, 1395; Angew. Chem. Int. Ed. 2015, 54, 2190; Angew. Chem. Int. Ed. 2015, 54, 5985; Langmuir 2017, 33, 13774]
Plasmonic Black Gold:
The conceptualization and development of "Black Gold" by Polshettiwar's group represent a significant milestone in plasmonic photocatalysis. "Black Gold" serves as a model system to study plasmonic hot electron generation and transfer, a phenomenon critical for enhancing photocatalytic activities under visible light. The ability of "Black Gold" to act as an artificial tree, mimicking natural photosynthesis by utilizing sunlight, water, and CO2, offers profound implications for the development of sustainable energy solutions.
[Selected publications: Chemical Science, 2019, 10, 6594; ACS Materials Lett. 2021, 3, 574; ACS Nano, 2023, 17, 4526; Nature Commun. 2023, 14, 2551; ACS Catalysis, 2023, 13, 7395; Nature Commun. 2024, 15, 713; Nature Commun. 2024, 15, 7974]
The conceptualization and development of "Black Gold" by Polshettiwar's group represent a significant milestone in plasmonic photocatalysis. "Black Gold" serves as a model system to study plasmonic hot electron generation and transfer, a phenomenon critical for enhancing photocatalytic activities under visible light. The ability of "Black Gold" to act as an artificial tree, mimicking natural photosynthesis by utilizing sunlight, water, and CO2, offers profound implications for the development of sustainable energy solutions.
[Selected publications: Chemical Science, 2019, 10, 6594; ACS Materials Lett. 2021, 3, 574; ACS Nano, 2023, 17, 4526; Nature Commun. 2023, 14, 2551; ACS Catalysis, 2023, 13, 7395; Nature Commun. 2024, 15, 713; Nature Commun. 2024, 15, 7974]
Defects as Catalytic Sites:
Traditionally, defects in nanomaterials were often viewed as imperfections that might hinder the material's properties or performance. However, Polshettiwar's research has shifted this perception by demonstrating how defects can be harnessed as active sites for catalysis, offering a new paradigm in the design and development of catalysts. This work not only highlights the role of defects in facilitating chemical reactions but also opens up new avenues for the design of catalysts that are metal-free and do not require complex organic ligands.
[Selected publications: Proc. Natl. Acad. Sci. U.S.A 2020, 117, 6383; Chemical Science, 2021, 12, 4267; J. Am. Chem. Soc. 2023, 145, 8634; ACS Materials Lett. 2023, 5, 715; Proc. Natl. Acad. Sci. U.S.A 2025, in press]
Traditionally, defects in nanomaterials were often viewed as imperfections that might hinder the material's properties or performance. However, Polshettiwar's research has shifted this perception by demonstrating how defects can be harnessed as active sites for catalysis, offering a new paradigm in the design and development of catalysts. This work not only highlights the role of defects in facilitating chemical reactions but also opens up new avenues for the design of catalysts that are metal-free and do not require complex organic ligands.
[Selected publications: Proc. Natl. Acad. Sci. U.S.A 2020, 117, 6383; Chemical Science, 2021, 12, 4267; J. Am. Chem. Soc. 2023, 145, 8634; ACS Materials Lett. 2023, 5, 715; Proc. Natl. Acad. Sci. U.S.A 2025, in press]
Nanosponges of Solid Acid:
The Polshettiwar group overcame significant synthetic challenges to develop "Acidic Amorphous Aluminosilicate," a novel material that uniquely combines the strong acidity of zeolites with the textural properties of aluminosilicates, featuring a distinctive nanosponge morphology. This innovation has demonstrated exceptional efficacy in converting plastics to chemicals and CO2 to fuel, showcasing remarkable selectivity and stability.
[Selected publications: Nature Commun. 2020, 11, 3828; Nature Commun. 2024, 15, 6899; Chemical Science 2024, 15, 20240]
The Polshettiwar group overcame significant synthetic challenges to develop "Acidic Amorphous Aluminosilicate," a novel material that uniquely combines the strong acidity of zeolites with the textural properties of aluminosilicates, featuring a distinctive nanosponge morphology. This innovation has demonstrated exceptional efficacy in converting plastics to chemicals and CO2 to fuel, showcasing remarkable selectivity and stability.
[Selected publications: Nature Commun. 2020, 11, 3828; Nature Commun. 2024, 15, 6899; Chemical Science 2024, 15, 20240]
Design of CO2 Sorbents using DFNS:
Hybrid materials by functionalization of fibrous nano-silica were synthesized for efficient CO2 capture. Functionalization was achieved by simple physisorption and covalent attachment of various amine molecules. DFNS-TEPAads was compared with its MCM-41 counterpart (MCM-41/TEPAads) and was found far better in terms of CO2 capture capacity, the rate of adsorption and stability.
(Ref- Chem. Sci., 2012, 3, 4222; J. Mat. Chem. A. 2016, 4, 7005 )
Hybrid materials by functionalization of fibrous nano-silica were synthesized for efficient CO2 capture. Functionalization was achieved by simple physisorption and covalent attachment of various amine molecules. DFNS-TEPAads was compared with its MCM-41 counterpart (MCM-41/TEPAads) and was found far better in terms of CO2 capture capacity, the rate of adsorption and stability.
(Ref- Chem. Sci., 2012, 3, 4222; J. Mat. Chem. A. 2016, 4, 7005 )
