Efficient Hydrogen Evolution under Visible Light by Bimetallic Phosphide NiCoP Combined with g‐C 3 N 4 /CdS S‐Scheme Heterojunction

4-Methyl-5-vinyl thiazole modified Ni-MOF/g-C3N4/CdS composites for efficient photocatalytic hydrogen evolution without precious metal cocatalysts

The construction of heterojunction systems is an effective way to efficiently generate hydrogen by water photolysis. In this work, Ni-MOF (trimesic acid, (BTC)) and g-C3N4 (denoted as CN) were combined, and then Ni-MOF/CN was modified by 4-Methyl-5-vinyl thiazole (denoted as MVTh). Finally, CdS was loaded on the surface of Ni-MOF/CN/MVTh to prepare the photocatalyst Ni-MOF/g-C3N4/MVTh/CdS (denoted as Ni/CN/M/Cd) with a triangular closed-loop path heterojunction for the first time. As a photocatalyst without precious metal cocatalysts, Ni/CN/M/Cd displayed high H2 evolution (17.844 mmol·g-1·h-1) under an optimum CdS loading of 40 wt%. The H2 evolution rate was approximately 79 times that of Ni-MOF/CN and exceeded those of almost all catalysts based on MOF/CN in the literature. The triangular closed-loop heterojunction formed between Ni-MOF, g-C3N4, and CdS could realize the directional migration of photocarriers and significantly diminished the transfer resistance of carriers. The Ni2+ in Ni-MOF provided many cocatalytic sites for H2 evolution via g-C3N4 and CdS. Furthermore, charge carrier separation in Ni-MOF/CN/CdS improved after the innovative addition of MVTh. This study provides a reference for the construction of a closed-loop heterojunction system without precious metal cocatalysts.

Electronic interaction of ruthenium species on bimetallic phosphide for superior electrocatalytic hydrogen generation

The exploitation of high-performance electrocatalysts to achieve the economic electrocatalytic hydrogen evolution reaction (HER) is significant in generating H2 fuel. Enhancing the activity of the carrier catalyst by modifying trace precious metals is one of the important strategies. Herein, a hybrid material is developed by incorporating trace Ru species into a bimetallic phosphide (NiCoP) matrix on nickel foam (NF), showing a superior catalytic activity for HER. The Ru-NiCoP/NF hybrid material has plenty of heterointerfaces, improved electronic interaction, and small interfacial charge transfer resistance, improving the reaction kinetics of the HER. Remarkable, the Ru-NiCoP/NF provides a low overpotential of 96 mV at the current density of 50 mA cm-2 and high stability in 1.0 M KOH solution presenting a promising potential for hydrogen production. In addition, the Ru-NiCoP/NF sample exhibits the highest TOF value of 0.54 s-1 at an overpotential of 100 mV, which outperforms the commercial Ru/C catalyst. This study offers a promising approach for the synthesis of other precious metal supported hybrid materials.

Development of robust multifunctional CrNiCo-P/GCN catalyst for oxygen evolution reaction, electrochemical sensing, and photodegradation of roxarsone

In this study, we designed a CrNiCo-P/GCN composite for use as a high-performance multifunctional catalyst for the oxygen evolution reaction (OER), electrochemical determination, and photodegradation of roxarsone (ROX). CrNiCo-P/GCN demonstrates favorable charge resistance and electrical conductance due to its intrinsic properties. It exhibits an admirable OER overpotential of 290 mV with a lower Tafel plot value of 125 mV dec^-1 in alkaline media and compared with the control samples. Furthermore, this composite also demonstrates high performance in electrochemical sensing of ROX over a wide concentration range of 1-413 μM with a lower limit of detection (LOD) of 31 nM in phosphate buffer. Moreover, this composite is a promising electrocatalyst for ROX sensors in practical analysis and also possesses excellent photodegradation of ROX under visible light irradiation.