Photoconductive Curved-Nanographene/Fullerene Supramolecular Heterojunctions.

This study presents synthesis and characterizations of two novel curved nanographenes that strongly bind with fullerene C60 to form photoconductive heterojunctions. Films of the self-assembled curved nanographene/fullerene complexes, which served as the photoconductive layer, generated a significant photocurrent under light irradiation. Gram-scale quantities of these curved nanographenes (TCR and HCR) as the "crown" sidewalls can be incorporated into a carbon nanoring to form molecular crowns, and the molecular structure of C60 @TCR is determined by single-crystal X-ray diffraction. The UV/Vis absorption and emission spectra, and theoretical studies revealed their unique structural features and photophysical properties. Time-resolved spectroscopic results clearly suggest fast photoinduced electron transfer process in the supramolecular heterojunctions.

Highly Efficient and Stable Water-Oxidation Electrocatalysis with a Very Low Overpotential using FeNiP Substitutional-Solid-Solution Nanoplate Arrays.

The development of efficient water-oxidation electrocatalysts based on inexpensive and earth-abundant materials is significant to enable water splitting as a future renewable energy source. Herein, the synthesis of novel FeNiP solid-solution nanoplate (FeNiP-NP) arrays and their use as an active catalyst for high-performance water-oxidation catalysis are reported. The as-prepared FeNiP-NP catalyst on a 3D nickel foam substrate exhibits excellent electrochemical performance with a very low overpotential of only 180 mV to reach a current density of 10 mA cm-2 and an onset overpotential of 120 mV in 1.0 m KOH for the oxygen evolution reaction (OER). The slope of the Tafel plot is as low as 76.0 mV dec-1 . Furthermore, the long-term electrochemical stability of the FeNiP-NP electrode is investigated by cyclic voltammetry (CV) at 1.10-1.55 V versus reversible hydrogen electrode (RHE), demonstrating very stable performance with negligible loss in activity after 1000 CV cycles. This present FeNiP-NP solid solution is thought to represent the best OER catalytic activity among the non-noble metal catalysts reported so far.

A Copper Porphyrin-Based Conjugated Mesoporous Polymer-Derived Bifunctional Electrocatalyst for Hydrogen and Oxygen Evolution.

Scalable and robust catalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are required for the implementation of water splitting technologies as a globally applicable method of producing renewable hydrogen. Herein, we report nitrogen-enriched porous carbon materials containing copper/copper oxide, derived from copper porphyrin-based conjugated mesoporous polymers (CMPs), as a bifunctional catalyst for both HER and OER. These catalysts have a high surface area, unique tubular structure, and strong synergistic effect of copper/copper oxide and porous carbons, resulting in excellent performance for water splitting. Under optimal conditions, the catalyst exhibits a quite low overpotential for OER (350 mV to reach 1.0 mA cm(-2) and 450 mV to reach 10 mA cm(-2) ) in alkaline media, which places it among the best copper-based water oxidation catalysts reported in the literature. Furthermore, the catalyst shows good catalytic activity for HER at a low overpotential (190 mV to reach 1.0 mA cm(-2) ) as well as a high current density (470 mV to reach 50 mA cm(-2) ). The results suggest that hybridized copper/carbon materials are attractive noble-metal-free catalysts for water splitting.

In situ generated highly active copper oxide catalysts for the oxygen evolution reaction at low overpotential in alkaline solutions.

Developing efficient water oxidation catalysts made up of earth-abundant elements has attracted much attention as a step toward for future clean energy production. Herein we report a simple one-step method to generate a low cost copper oxide catalyst film in situ from a copper(ii) ethylenediamine complex. The resulting catalyst has excellent activity toward the oxygen evolution reaction in alkaline solutions. A catalytic current density of 1.0 mA cm(-2) and 10 mA cm(-2) for the catalyst film requires the overpotentials of only ∼370 mV and ∼475 mV in 1.0 M KOH, respectively. This catalytic performance shows that the new catalyst is one of the best Cu-based heterogeneous OER catalysts to date.