Sayantan Chongdar

We developed a novel strategy for synthesizing a highly acidic microporous hybrid titanium phosphate material (H-TiPO_x) by incorporating 5-aminosalicylic acid (5-ASA) into the titanium phosphate framework. This new H-TiPO_x serves as a Brønsted acid catalyst, exhibiting remarkable total surface acidity of 5.9 mmol g⁻¹ and it efficiently catalyzes the acetalization of abundant biomass derived glycerol to solketal with over 99% selectivity.

With the aim of bringing future renewable energy resources into reality, searching for effective bifunctional electrocatalysts for overall water splitting, i.e. both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), can be considered pivotal. On the other hand, water electrolysis is being examined as an ideal technique to produce hydrogen on a massive scale. So far, most water electrolysers work effectively using either acidic or alkaline media. However, from the industrial perspective, today the development of noble metal-free, stable electrocatalysts for overall water splitting in neutral media is of paramount interest. This chapter discusses recent developments in bifunctional electrocatalysts. Particular attention is paid to cobalt-based, metal–organic framework (MOF)-based bifunctional electrocatalysts and those that work efficiently in neutral media. An example is presented with a Co–TDC electrocatalyst, obtained from thiophene-2,5-dicarboxylic acid, which exhibited a current density of 10 mA cm−2 at 1.96 V in 1 M phosphate-buffered saline solution, with almost 24 h stability for overall water splitting.

We report microwave assisted rapid synthesis of ZIF-9 nanocrystals. ZIF-9@xGO composites displayed selective electrocatalytic oxidation of benzyl alcohols (benzoic acid yield 84%, faradaic efficiency 88%) together with high H₂ production (273 mmol g⁻¹ h⁻¹).

A water-stable, microporous, luminescent Ni(II)-based metal-organic framework (MOF) (Ni-OBA-Bpy-18) with a 4-c uninodal sql topology was solvothermally synthesized using mixed N-, O-donor-directed π-conjugated co-ligands. The extraordinary performance of this MOF toward rapid monitoring of mutagenic explosive trinitrophenol (TNP) in aqueous and vapor phases by the fluorescence "Turn-off" technique with an ultralow detection limit of 66.43 ppb (K_sv: 3.45 × 10⁵ M^-1) was governed by a synchronous occurrence of photoinduced electron transfer-resonance energy transfer-intermolecular charge transfer (PET-RET-ICT) and non-covalent π···π weak interactions, as revealed from density functional theory studies. The recyclable nature of the MOF, detection from complex environmental matrices, and fabrication of a handy MOF@cotton-swab detection kit certainly escalated the on-field viability of the probe. Interestingly, the presence of electron-withdrawing TNP decisively facilitated the redox events of the reversible Ni^III/II and Ni^IV/III couples under an applied voltage based on which electrochemical recognition of TNP was realized by the Ni-OBA-Bpy-18 MOF/glassy carbon electrode, with an excellent detection limit of ∼0.6 ppm. Such detection of a specific analyte by MOF-based probe via two divergent yet coherent techniques is unprecedented and yet to be explored in relevant literature.

A new zinc phosphonate catalyst for the synthesis of tetra-cyclic carbonates, carbamates and polyurethanes using CO₂ as C1 source is reported.

In this feature article, we highlight various synthetic strategies for designing organic–inorganic hybrid porous materials, starting from their molecular building blocks, and their task-specific applications in energy and environmental research.