Salicylic Acid As a Tridentate Anchoring Group for <i>azo</i>-Bridged Zinc Porphyrin in Dye-Sensitized Solar Cells

Two series dyes of <i>azo</i>-bridged zinc porphyrins have been devised, synthesized, and performed in dye-sensitized solar cells, in which salicylic acids and <i>azo</i> groups were introduced as a new anchoring group and π-conjugated bridge <i>via</i> a simple synthetic procedure. The representation of the new dyes has been investigated by optical, photovoltaic, and electrochemical means. The photoelectric conversion efficiency of their DSSC devices has been improved compared with other DSSC devices sensitized by symmetrical porphyrin dyes. The results revealed that tridentate binding modes between salicylic acid and TiO₂ nanoparticles could enhance the efficiency of electron injection. The binding modes between salicylic acid and TiO₂ nanoparticles may play a crucial role in the photovoltaic performance of DSSCs

Strategy to Improve Photovoltaic Performance of DSSC Sensitized by Zinc Prophyrin Using Salicylic Acid as a Tridentate Anchoring Group

Three new zinc porphyrin dyes attached to ethynyl benzoic acid as an electron transmission and anchoring group have been designed, synthesized, and well-characterized. The performances of their sensitized solar cells have been investigated by optical, photovoltaic, and electrochemical methods. The photoelectric conversion efficiency of the solar cells sensitized by the dye with salicylic acid as an anchoring group demonstrated obvious enhancement when compared with that sensitized by the dye with carboxylic acid as an anchoring group. The density functional theory calculations and the electrochemical impedance spectroscopies revealed that tridentate binding modes could increase the efficiency of electron injection from dyes to the TiO₂ nanoparticles by more electron pathways

Palladium-Catalyzed Intramolecular Dearomatization of Indoles via Decarboxylative Alkynyl Termination

A highly diastereoselective dearomatization of indoles via palladium-catalyzed decarboxylative alkynyl termination was developed. This protocol provides dissimilar tetracyclic and tetrasubstituted indoline scaffolds bearing congested stereocenters, which led to operationally simple conditions, short time, and broad substrate scope. Additionally, this reaction system could be scaled to gram quantities in a satisfactory yield and diastereoselectivity

Bipolar charge collecting structure enables overall water splitting on ferroelectric photocatalysts

While ferroelectric materials are promising candidates for solar water splitting, most examples show poor activities. Here, authors prepare charge-collecting nanostructures on the positive and negative domains of BaTiO3 and demonstrate photocatalytic overall water splitting

Unraveling Sequential Oxidation Kinetics and Determining Roles of Multi-Cobalt Active Sites on Co₃O₄ Catalyst for Water Oxidation

The multi-redox mechanism involving multi-sites has great implications to dictate the catalytic water oxidation. Understanding the sequential dynamics of multi-steps in oxygen evolution reaction (OER) cycles on working catalysts is a highly important but challenging issue. Here, using quasi-operando transient absorption (TA) spectroscopy and a typical photosensitization strategy, we succeeded in resolving the sequential oxidation kinetics involving multi-active sites for water oxidation in OER catalytic cycle, with Co3O4 nanoparticles as model catalysts. When OER initiates from fast oxidation of surface Co2+ ions, both surface Co2+ and Co3+ ions are active sites of the multi-cobalt centers for water oxidation. In the sequential kinetics (Co2+ → Co3+ → Co4+), the key characteristic is fast oxidation and slow consumption for all the cobalt species. Due to this characteristic, the Co4+ intermediate distribution plays a determining role in OER activity and results in the slow overall OER kinetics. These insights shed light on the kinetic understanding of water oxidation on heterogeneous catalysts with multi-sites