Vasudevanpillai Biju

Isomeric indium bromide single crystals with fast green and delayed yellow emissions are developed. Face-shared InBr ₄ tetrahedra in the green-emitting crystal and unshared InBr ₄ tetrahedra in the yellow-emitting crystal distinguish the isomers.

Tuning platinum porphyrin loading on chitosan shifts photochemical activity from singlet oxygen generation toward enhanced cocatalyst-free H ₂ evolution in water (72.7 mmol g ⁻¹ h ⁻¹ ; AQY 0.4% at 405 nm).

Exciton–plasmon coupled enhanced absorption and emission rates, and photoluminescence intensity from halide perovskite quantum dots for high-performance solar cells, light-emitting diodes, lasers, and photocatalysts.

We demonstrate the colloidal synthesis of luminescent titanium nitride (TiN) quantum dots with multicolor emission and tunable band gaps, providing safer alternatives to metal chalcogenides and halide perovskites for solar cells and LEDs.

Halide perovskite supercrystals (or superlattices) are electronically coupled nanomaterials, such as nanocrystals, quantum dots, or nanoplatelets that offer collective optical and electronic properties distinct from those of their constituents.

We present a versatile approach to designing and utilizing high-performance nonmetal near-infrared (NIR) organic photocatalysts based on aromatic sulfones. Current NIR photocatalysts are mainly metal complexes and inorganic materials, while the few reported nonmetal organic NIR photocatalysts primarily use photosensitization to produce active species such as singlet oxygen. Our sulfone-rosamine-based redox photocatalyst 3 demonstrates exceptional capabilities, including high ability for metal-free photo-oxidative bromination, intrinsically oxygen-independent redox reactions, and remarkable photostability with a turnover number (TON) exceeding 2800. We showcase the photocatalyst's efficacy in photo-oxidative bromination of aromatic compounds under 738 nm illumination. The reaction mechanism is elucidated through electrochemical studies, time-resolved spectral measurements, and DFT calculations. Transient absorption measurements using the randomly interleaved pulse train (RIPT) method reveal the photoexcited state of 3 in the reaction. The photocatalyst 3 demonstrated its versatility for several aromatic substances, including those exhibiting strong light absorption in the visible region. This aromatic sulfone-based approach offers a robust blueprint for developing nonmetal NIR organic photocatalysts with superior photo-oxidation ability and stability, addressing key limitations of conventional organic NIR photocatalysts.