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Two novel metal‐free organic dyes, namely the mono‐anchoring KMT1 and di‐anchoring KMT2 dyes, have been synthesized to function as photosensitizers for utilizing in photocatalytic hydrogen production systems. They adopt the donor‐donor‐π‐acceptor and donor‐donor‐(−π‐acceptor)2 configurations, respectively, featuring triphenylamine and fluorene moieties as electron donors, thiophene as the π‐bridges and cyanoacrylic acid as the acceptors/anchoring groups. It was found that the photocatalytic performance of the di‐anchoring dye significantly outperforms that of its mono‐anchoring counterpart. KMT2‐based photocatalytic system demonstrated remarkable performance, producing 3520 μmol (84.9 mL) of hydrogen over a span of 257 hours under blue light irradiation, with a turnover number (TON) of 56300, a turnover frequency (TOFi) of 1862.7 h−1, an initial hydrogen production activity (activityi) of 1164180 and an apparent quantum yield (AQYi %) of 19.9. This performance is among the top‐tier when compared to other dyes used in similar photocatalytic systems. The results clearly illustrate that the di‐anchoring dye possesses several advantages, including a broad absorption spectrum, higher absorptivity, and a relatively slower charge recombination rate. These attributes collectively contribute to its superior overall performance in photocatalysis. [ABSTRACT FROM AUTHOR]

The development of base metal electrodes that can act as active and stable oxygen generating electrodes in water electrolysis systems, especially at low pH levels, remains a challenge. The use of suspensions as electrolytes for water splitting has until recently been limited to photoelectrocatalytic approaches. A high current density (j=30 mA/cm2) for water electrolysis has been achieved at a very low oxygen evolution reaction (OER) potential (E=1.36 V vs. RHE) using a SnO2/H2SO4 suspension–based electrolyte in combination with a steel anode. More importantly, the high charge–to–oxygen conversion rate (Faraday efficiency of 88 % for OER at j=10 mA/cm2 current density). Since cyclic voltammetry (CV) experiments show that oxygen evolution starts at a low, but not exceptionally low, potential, the reason for the low potential in chronoamperometry (CP) tests is an increase in the active electrode area, which has been confirmed by various experiments. For the first time, the addition of a relatively small amount of solids to a clear electrolyte has been shown to significantly reduce the overpotential of the OER in water electrolysis down to the 100 mV region, resulting in a remarkable reduction in anode wear while maintaining a high current density. [ABSTRACT FROM AUTHOR]

Electrochemical water oxidation is an important anodic process necessary to support many cathodic fuel forming processes. Inexpensive materials capable of water oxidation catalysis are necessary to render renewable energy technologies affordable. In this study, titanium diboride (TiB2) microparticles were explored as an oxygen‐evolution reaction (OER) electrocatalyst in 1.0 M HClO4. An overpotential of 560±20 mV was required to generate a current density of 10 mA cm−2 with a Faradaic efficiency >96 %. TiB2 exhibited a dissolution rate of 0.24 μg cm−2 h−1 which is the slowest rate observed to date for an earth‐abundant OER catalyst in acidic electrolyte at pH 0. [ABSTRACT FROM AUTHOR]

Visible‐light triggerable, stable, organic material‐based photocatalysts that can function in alkaline media without the necessity of sacrificial agent for hydrogen production are highly sought after. Here, we report a novel supramolecular photocatalyst that confers the aforementioned features. This supramolecular photocatalyst (TPP‐4CB7) is synthesized through the conjugation of monohydroxylated cucurbit(7)uril (CB7) hosts to a suitably substituted tetraphenyl porphyrin. Although TPP‐4CB7 by its own preforms as an efficient visible light triggered photocatalyst, the hydrogen production efficiency is significantly enhanced upon mixing with TiO2. The resulting nanocomposite (TPP‐CB‐TiO2@Pt) is observed to exhibit remarkable electrophotocatalytic activity under visible light and produces hydrogen (onset potential −10 mV, turn over frequency (TOF) 0.202 s−1, 24.5 mmol h−1 g−1) from water splitting without any significant degradation during four runs (5 h each) in alkaline media and in the absence of sacrificial agent. [ABSTRACT FROM AUTHOR]

Front Cover: Novel Supramolecular Photocatalyst Based on Conjugation of Cucurbit[7]uril to Non-Metallated Porphyrin for Electrophotocatalytic Hydrogen Generation from Water Splitting (ChemCatChem 13/2019) B The Front Cover b shows solar energy promoted photoelectrocatalytic water splitting for hydrogen generation using a supramolecular photocatalyst. In their Communication, Dönüs Tuncel and co-workers synthesize a novel, visible light triggerable, stable supramolecular photocatalyst based on conjugation of cucurbit[7]uril to non-metallated porphyrin. [Extracted from the article]