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17 pages, 4145 KiB

Open AccessArticle

MOF Template-Derived Carbon Shell-Embedded CoP Hierarchical Nanosheet as Bifunctional Catalyst for Overall Water Splitting

by Mei-Jun Liu, Fu-Hao Yang, Ji-Cheng Mei, Xu Guo, Hua-Yang Wang, Meng-Yao He, Yu-Ang Yao, Hai-Feng Zhang and Cheng-Bin Liu

Nanomaterials 2023, 13(17), 2421; https://0-doi-org.brum.beds.ac.uk/10.3390/nano13172421 - 25 Aug 2023

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Abstract

The design of earth-abundant and highly efficient bifunctional electrocatalysts for hydrogen evolution and oxygen evolution reactions (HER/OER) is crucial for hydrogen production through overall water splitting. Herein, we report a novel nanostructure consisting of vertically oriented CoP hierarchical nanosheet arrays with in situ-assembled [...] Read more.

The design of earth-abundant and highly efficient bifunctional electrocatalysts for hydrogen evolution and oxygen evolution reactions (HER/OER) is crucial for hydrogen production through overall water splitting. Herein, we report a novel nanostructure consisting of vertically oriented CoP hierarchical nanosheet arrays with in situ-assembled carbon skeletons on a Ti foil electrode. The novel Zeolitic Imidazolate Framework-67 (ZIF-67) template-derived hierarchical nanosheet architecture effectively improved electrical conductivity, facilitated electrolyte transport, and increased the exposure of the active sites. The obtained bifunctional hybrid exhibited a low overpotential of 72 mV at 10 mA cm⁻² and a small Tafel slope of 65 mV dec⁻¹ for HER, and an improved overpotential of 329 mV and a Tafel slope of 107 mV dec⁻¹ for OER. Furthermore, the assembled C@CoP||C@CoP electrolyzer showed excellent overall water splitting performance (1.63 V) at a current density of 10 mA cm⁻² and superior durability. This work provides a structure engineering strategy for metal–organic framework (MOF) template-derived hybrids with outstanding electrocatalytic performance. Full article

(This article belongs to the Special Issue Green Catalysis in Nanomaterials—Photocatalysis and Electrocatalysis)

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19 pages, 6829 KiB

Open AccessArticle

Efficient Dual-Function Catalyst: Palladium–Copper Nanoparticles Immobilized on Co-Cr LDH for Seamless Aerobic Oxidation of Benzyl Alcohol and Nitrobenzene Reduction

by Linah A. Alzarea, Mosaed S. Alhumaimess, Ibrahim Hotan Alsohaimi, Hassan M. A. Hassan, M. R. El-Aassar, Amr A. Essawy and Haitham Kalil

Nanomaterials 2023, 13(13), 1956; https://0-doi-org.brum.beds.ac.uk/10.3390/nano13131956 - 27 Jun 2023

Cited by 2 | Viewed by 1063

Abstract

Layered double hydroxides (LDHs) present exciting possibilities across various industries, ranging from catalytic applications to water remediation. By immobilizing nanoparticles, LDHs’ characteristics and functionality can be enhanced, allowing for synergetic interactions that further expand their potential uses. A simple chemical method was developed [...] Read more.

Layered double hydroxides (LDHs) present exciting possibilities across various industries, ranging from catalytic applications to water remediation. By immobilizing nanoparticles, LDHs’ characteristics and functionality can be enhanced, allowing for synergetic interactions that further expand their potential uses. A simple chemical method was developed to produce well-dispersed Pd-Cu NPs on a Co-Cr LDH support using a combination of in situ coprecipitation/hydrothermal and sol-immobilization techniques. The Pd-Cu@Co-Cr LDH catalysts was obtained, showing its catalytic activity in promoting the aerobic oxidation of alcohols and enabling the reduction of nitro-compounds through NaBH₄ mediation. The physicochemical properties of the prepared catalyst were comprehensively investigated utilizing a range of analytical techniques, comprising FTIR, XRD, XPS, TGA, nitrogen adsorption isotherm, FESEM, and HRTEM-EDX. The findings showed the significance of immobilizing the bimetallic Pd-Cu nanoparticles on the Co-Cr LDH via an exceptional performance in the aerobic oxidation of benzyl alcohol (16% conversion, 99.9% selectivity to benzaldehyde) and the reduction of nitrobenzene (98.2% conversion, rate constant of 0.0921 min⁻¹). The improved catalytic efficacy in benzyl alcohol oxidation and nitrobenzene reduction on the Pd-Cu@Co-Cr LDH catalyst is attributed to the uniform distribution and small size of the Pd-Cu NPs as active sites on the Co-Cr LDH surface. The prepared catalyst demonstrated exceptional stability during repeated runs. This study paves the way for multiple opportunities in tailoring, producing, and precisely controlling catalysts for various organic transformation reactions. Full article

(This article belongs to the Special Issue Green Catalysis in Nanomaterials—Photocatalysis and Electrocatalysis)

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Review

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14 pages, 4357 KiB

Open AccessFeature PaperReview

Revisited Catalytic Hydrogen Evolution Reaction Mechanism of MoS₂

by Yuhao He, Xiangpeng Chen, Yunchao Lei, Yongqi Liu and Longlu Wang

Nanomaterials 2023, 13(18), 2522; https://0-doi-org.brum.beds.ac.uk/10.3390/nano13182522 - 08 Sep 2023

Cited by 1 | Viewed by 790

Abstract

MoS₂ has long been considered a promising catalyst for hydrogen production. At present, there are many strategies to further improve its catalytic performance, such as edge engineering, defect engineering, phase engineering, and so on. However, at present, there is still a great [...] Read more.

MoS₂ has long been considered a promising catalyst for hydrogen production. At present, there are many strategies to further improve its catalytic performance, such as edge engineering, defect engineering, phase engineering, and so on. However, at present, there is still a great deal of controversy about the mechanism of MoS₂ catalytic hydrogen production. For example, it is generally believed that the base plane of MoS₂ is inert; however, it has been reported that the inert base plane can undergo a transient phase transition in the catalytic process to play the catalytic role, which is contrary to the common understanding that the catalytic activity only occurs at the edge. Therefore, it is necessary to further understand the mechanism of MoS₂ catalytic hydrogen production. In this article, we summarized the latest research progress on the catalytic hydrogen production of MoS₂, which is of great significance for revisiting the mechanism of MoS₂ catalytic hydrogen production. Full article

(This article belongs to the Special Issue Green Catalysis in Nanomaterials—Photocatalysis and Electrocatalysis)

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