Integration of Semiconductor Oxide and a Microporous (3,10)-Connected Co₆-Based Metal–Organic Framework for Enhanced Oxygen Evolution Reaction

Abstract

Developing high-efficiency and cost-effective electrocatalytic oxygen evolution reaction (OER) catalysts would determine the future distributions of energy conversion technologies. Metal–organic frameworks (MOFs), with unsaturated active metal sites, functionalized organic linkers, and large surface areas, are emerging heterogeneous electrocatalysts for the water oxidation process. Herein, we report an oxygen-evolving microporous (3,10)-connected Co6-based MOF (denoted as CTGU-14) for the electrocatalytic OER. Moreover, the integration of Co-MOF and SnO2, SnO2 (15%) & CTGU-14 composite attains remarkable electrochemical OER performance with a small Tafel slope of 68 mV·dec–1, a positive overpotential of 388 mV at 10 mA·cm–2, and overall durability in an alkali medium. The superior OER activities might be ascribed to more convenient electron transfer from the SnO2 additive to the electrode medium, effective surface area and unsaturated active cobalt centers, and more beneficial delivery for hydroxy radicals in the microporous Co-MOF skeleton in the process of the OER.

V═O Functionalized {Tm2}–Organic Framework Designed by Postsynthesis Modification for Catalytic Chemical Fixation of CO2 and Oxidation of Mustard Gas

“…Although it is a huge challenge to successfully assemble the targeted porous Ln-MOFs, their excellent properties in the aspects of selective separation and storage, luminescence and recognition, and catalysis continue to attract remarkable attention from many scientists. Especially, the fact that the rich coordination geometry of Ln 3+ ions due to the ratio of charge to radius (Z/R) and abundant hybrid orbitals of f n d 2+m sp 3 (n = 0−3, m = 1−3) gives them a wide coordination number range, which grants octa-or nonacoordinated Ln 3+ ions the ability to polarize small guest molecules, such as CO 2 , SO 2 , and H 2 S. 20,21 Recently, one porous Eu-MOF reported by Zhao and coworkers exhibited an efficient catalytic performance for the chemical fixation of CO 2 , 22 which confirmed that Ln-MOFs are subjects worthy of study due to the fact that the high coordination characteristics of Ln III ions give them ideal Lewis acid sites. Therefore, the exploration of syntheses and optimization for Ln-based host skeletons by increasing highly active sites to achieve targeted catalysts has become inevitable.…”

Nanochannel-based heterometallic {ZnIIHoIII}–organic framework with high catalytic activity for the chemical fixation of CO2

“…2 , the maximum absorption of CO 2 at 273 K and 298 K was 93.44 cm 3 g −1 and 64.99 cm 3 g −1 , respectively, which are higher than that in the literature, such as for NUC-5, MOF-5, and Uio-66. 18 Simultaneously, incomplete adsorption isotherms and CO 2 desorption lead to a moderate hysteresis loop, which confirms the strong interaction between the host and guest. Furthermore, in quantify the binding force between the CO 2 molecules and the framework of NUC-30, Q st was calculated using the virial method with the resulting value at zero coverage being 25.8 kJ mol −1 , which implies that the adsorbed CO 2 molecules can be easily released, allowing the host framework of NUC-30 to be regenerated, as shown in Fig.…”

Alkali‐Etched Ni(II)‐Based Metal–Organic Framework Nanosheet Arrays for Electrocatalytic Overall Water Splitting

“…Moreover, the peak at 530.9 eV probably belongs to a high number of oxygen vacancies (O v ), which is attributed to the breaking of NiO bonds after etching treatment. [ 31 ] It should be noted the oxygen vacancies is favorable for decreasing the adsorption energy of intermediates and facilitating the desorption of intermediates on active sites in electrocatalysis. [ 28,32 ]…”