Trapping [PMo12O40]3− clusters into pre-synthesized ZIF-67 toward MoxCoxC particles confined in uniform carbon polyhedrons for efficient overall water splitting

et al. 2019

NPG Asia Mater

Self Cite

Driving the electrocatalytic hydrogen evolution reaction (HER) with solar-energy cells is considered a green and sustainable way to produce H 2 . Herein, CoO-Mo 2 N hollow heterojunctions were designed for effective HER based on the combined virtues of the hollow structure and heterojunctions. The hollow CoMoO 4 -Co(OH) 2 precursor was first synthesized via the reaction of Co 2+ from ZIF-67 with MoO 4 2− and OH − in a Na 2 MoO 4 solution. A series of experiments indicate the formation of the hollow Co-Mo-O precursor followed a mechanism analogous to the nanoscale "Kirkendall Effect". After heating in NH 3 , the CoO-Mo 2 N hollow heterostructure was obtained. The Mo species in the precursor played an important role in maintaining the morphology under nitridation treatment. The hollow structure is favorable for contact and diffusion of electrolyte with (in) catalysts, while the CoO in CoO-Mo 2 N is favorable for the dissociation of water. Both promote the HER. Under optimized conditions, the hollow catalyst exhibited good HER performance with an overpotential of 65 mV at 10 mA cm −2 in 1 M KOH. The performance is better than that of many nonprecious metal-based catalysts. An electrolyzer composed of CoO-Mo 2 N heterojunctions as the cathode and NiFe-LDH as the anode can be driven by a solar cell to achieve effective overall water splitting. The adjudication of MOFs makes the route promising for the design of robust catalysts for advanced application.

Section: Synthesis Of Zif-67mentioning

confidence: 99%

Section: Electrochemical Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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CoO-Mo2N hollow heterostructure for high-efficiency electrocatalytic hydrogen evolution reaction

et al. 2019

NPG Asia Mater

Self Cite

“…[38] Molybdenum-based compounds are importantm aterials in many respects (e.g.,e lectroopticala nd other types of catalysts) [39,40] Mo is easily combined with polyanions, which makes molybdenum-based materials diverseand applicable in differentfields. [41][42][43][44] The high-magnification SEM images in Figure 2c learly show the morphologies of hollow structures with boreholes. The low-magnification SEM images in FigureS1s how the increasing diameter of the holes with the increasingP OM dose.…”

Section: Resultsmentioning

confidence: 91%

PBA@POM Hybrids as Efficient Electrocatalysts for the Oxygen Evolution Reaction

Wang

Chemistry An Asian Journal

et al. 2019

To realize the effective conversion of renewable energy through water decomposition,e fficient electrocatalysts for the oxygen evolution reaction (OER) are essential. In this article, PBA@POM was successfully prepared with aP russian blue analogue (PBA) as the initial structure. Af acile hydrothermalp rocess is reported for obtaining PBA@POM by etching the cubic PBA with as trong Brønsted acid, H 3 PMo 12 O 40 (HPMo). The hollow cube structure not only exposes more active sites but also promotes electron transport, whichr esultsi ne xcellent electrocatalytic activity for the OER. Compared with the PBA, which initially simply adhered to POM, the optimum PBA@POM hybrids display remarkably enhanced OER catalytic activity,w ith an almost constant overpotential of 440 mV at a current density of 10 mA cm À2 andasmall Ta fel slope (23.45 mV dec À1 ). The facilelyp repared PBA@POM with good electrochemical activity and stabilityp romises great potential for the OER.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

“…The EGC has three isolated peaks in its C1 ss pectrum at 284.6, 286.7 and 288.9 eV (Figure 1b), whicho riginate from CÀC, CÀ O, and C=O. [61] This confirms that, during the electrochemical strippingp rocess, some carbon atoms are oxidized with generation of CÀOa nd C=Ob onds. In raw graphite foil, only CÀC exists, as illustrated by the peak at 284.6 eV in the C1 ss pectrum ( Figure 1c).…”

Section: Structural Characterization Of Egcmentioning

confidence: 54%

A Polyoxometalate‐Based Binder‐Free Capacitive Deionization Electrode for Highly Efficient Sea Water Desalination

Liu

et al. 2020

Chemistry A European J

Capacitive deionization is a promising technique in sea water desalination. Compared with common electrodes, mixed capacitive‐deionization electrodes exhibit better performance in sea water desalination because they integrate pseudocapacitance and electric double‐layer capacitance in one system. Herein, a 3D binder‐free mixed capacitive‐deionization electrode was fabricated by direct electrodeposition of SiW12O404− and polyaniline on a 3D exfoliated graphite carrier. In this electrode, SiW12O404−/polyaniline composite particles with a size of about 100–120 nm are dispersed homogenously on the 3D exfoliated graphite carrier. Its specific capacitance reaches 352 F g−1 at 1 A g−1. With increasing current from 1 to 20 A g−1, the specific capacitance only decays by 32 %. When employed in sea water desalination, the performance of this mixed capacitive‐deionization electrode is also excellent. At 1.2 V, the salt adsorption capacity of this mixed electrode reaches 23.1 mg g−1 with a salt adsorption rate of 1.38 mg g−1 min−1 in 500 mg L−1 NaCl. The performance of this electrode is well retained after 30 cycles. The excellent sea water desalination performance originates from the synergistic effect between SiW12O404− and polyaniline. This work has developed polyoxometalate as a new material for capacitive‐deionization electrodes.