Subrata Mandal

A UiO-67 MOF functionalized with [Ru(bpy) ₃ ] ²⁺ and Mn ²⁺ ions is active in light-driven amine oxidation. The oxidation via photosensitized singlet oxygen and electron transfer to manganese was evaluated.

The four Zr₈O₆‐based metal‐organic frameworks (MOFs), porous coordination network (PCN) 221 M, comprising earth‐abundant metalloporphyrin tetracarboxylate (M‐TCPP, M: 2 H, Zn, Ni, and a mixture of 1:1 Zn and Ni), are investigated for light‐driven H₂ evolution reaction (HER) in water. Under the irradiation of a 405 nm light emitting diode source and in the presence of triethanolamine (TEOA) as a sacrificial electron donor, the photocatalytic HER activity of PCN 221 varies with the metal center in the porphyrin linker. Among the tested MOFs, the Zn‐porphyrin derivative (PCN 221 Zn) produces H₂ at a TON = 4, which is about seven times greater than that of homogeneous Zn‐TCPP (0.6) and superior to its 2 H (2.7), Ni (0.40), and ZnNi (1.6) analogs. Detailed photochemical studies via time‐resolved and steady‐state spectroscopy reveal two distinct charge transfer pathways: Direct H₂ evolution from Zn‐TCPP itself, and electron transfer from the Zn‐TCPP photosensitizer to the Zr₈O₆ SBU catalytic sites. The improved HER performance of PCN 221 Zn is attributed to its favorable features, such as optical absorption, excited‐state properties, and charge separation dynamics, as well as the coordination of TEOA. This study provides fundamental insights into the design of MOF‐based heterogeneous photocatalysts exploiting earth‐abundant metal‐based porphyrin for solar fuel generation.

Light‐driven hydrogen (H₂) evolution in water is performed using a series of cobalt‐based Prussian blue analogs (MCo PBAs) with M^II₃[Co^III(CN)₆]₂, M = Co, Ni, Cu, Zn embedded in phospholipid bilayers with the amphiphilic ruthenium‐based photosensitizer RuC₉. Hydrophobic surface functionalization of MCo PBA nanoparticles with oleylamine facilitates close proximity of the PBA to the photosensitizer within lipid bilayers of vesicles, enhancing photocatalytic performance. The type of metal and rigidity of the lipid environment significantly influences hydrogen evolution reaction efficiency, with the trend: Ni > Co > Zn > Cu and DMPC > DOPC > DPPC. Among these, NiCo PBA in DMPC: (14:0 PEG2000 PE) vesicles shows the highest efficiency, with a ninefold increase in H₂ production compared to the conventional aqueous system. This sustained activity is attributed to the efficient electron transfer and the scaffold's stability. This study provides valuable insights for the development of scalable and cost‐effective photocatalytic technologies.

Metal–organic frameworks (MOFs) integrate photoactive and catalytic entities within a 3D structure. This review classifies photocatalytic MOFs by photosensitizer and catalyst localization and their roles in artificial photosynthesis.

Distinct functional materials in their combined form in a well-designed hybrid architecture offer great possibilities for creating a highly active photocatalytic system. Herein, a uniform multipod-shaped ZnO is synthesized through a natural template assisted route and progressively integrated with Ag nanoparticles (NPs) and Bi₂S₃ to form a three-component (3C) ternary photocatalytic system by a facile, two -step wet chemical approach. Encapsulation of polycrystalline Bi₂S₃ and assimilation of Ag NPs in between the interface of ZnO and Bi₂S₃ in the ternary hybrid are confirmed from electron microscopy and X-ray photoelectron spectroscopy, which resulted in improved UV–vis absorption, charge separation efficiency, and photocurrent response evaluated from optical absorption spectroscopy, photoluminescence, and photoelectrochemical cell measurements. This ternary hybrid shows high photoredox activity toward the hydrogen evaluation reaction (HER) (218.7 μmol h^–1 g^–1) and methyl orange (MO) oxidation (k = 3.21 × 10^–2 min^–1) compared to their binary and single counterparts. Moreover, on the basis of the estimation of the predominant active species (O₂^•–, ^•OH) in the photoredox catalysis and band edge positions from the Mott–Schottky plot, it was determined that both binary ZnO [email protected]₂S₃ and ternary ZnO multipod [email protected]₂S₃ hybrids undergo a Z-scheme electron transfer mechanism under irradiation of light. Here, the Ag ingredient in the ternary hybrids acts as an interfacial charge-transfer mediator to accelerate the Z-scheme electron transfer between Bi₂S₃ and ZnO along with plasmonic photosensitization to trigger the generation of plasmon-induced hot electrons. Such a cooperative concurrent dual role of Ag NPs in the Z-scheme ternary hybrid system considerably boosts the photoredox performance compared to direct Z-scheme binary hybrids. This work will enlighten and uncover the essential roles of metal NPs along with their cooperative synergy in Z-scheme photocatalytic systems as a prototypical example for substantial solar energy conversion.

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