Trimetallic Spinel NiCo_2−xFe_xO₄ Nanoboxes for Highly Efficient Electrocatalytic Oxygen Evolution

Abstract

The development of efficient and low‐cost electrocatalysts toward the oxygen evolution reaction (OER) is critical for improving the efficiency of several electrochemical energy conversion and storage devices. Here, we report an elaborate design and synthesis of porous Co‐based trimetallic spinel oxide nanoboxes (NiCo2−xFexO4 NBs) by a novel metal‐organic framework engaged strategy, which involves chemical etching, cation exchange, and subsequent thermal oxidation processes. Owing to the structural and compositional advantages, the optimized trimetallic NiCo2−xFexO4 NBs (x is about 0.117) deliver superior electrocatalytic performance for OER with an overpotential of 274 mV at 10 mA cm−2, a small Tafel slope of 42 mV dec−1, and good stability in alkaline electrolyte, which is much better than that of Co‐based bi/monometallic spinel oxides and even commercial RuO2.

Activating the lattice oxygen oxidation mechanism in amorphous molybdenum cobalt oxide nanosheets for water oxidation

“…MOFs are crystalline materials with an ordered topological structure that are often used as template for the engineering of porous nanostructured electrocatalysts. 49–51 We combined this approach with the hydrolysis of an ammonium salt and the simultaneous MOF etching to prepare Mo–Co-based porous materials. A scheme of the synthesis process is displayed in Fig.…”

Synergistically enhanced iron and zinc bimetallic sites as an advanced ORR electrocatalyst for flow liquid rechargeable Zn–air batteries

“…32–34 Compared to the pure TA, the peak intensity of C–OH stretching at 1027 cm −1 decreased, the peak intensity of asymmetric R–O–R′ stretching at 1115 cm −1 increased, and the red shift of the specific broad O–H band at 3390 cm −1 occurred, and a characteristic peak at 1384 cm −1 also appeared in TA–Fe and TA–Fe–PI attributed to the Fe–O band, suggesting that TA could also be used for chelating with ferric ions. 35,36 Therefore, it could be concluded that the TA–Fe–PI composite had been successfully prepared.…”

Defect‐Rich High‐Entropy Oxide Nanosheets for Efficient 5‐Hydroxymethylfurfural Electrooxidation

“…Meanwhile, the Raman spectrum of P-HEOs shows three features of E g (350 cm À1 ), F 2g (515 cm À1 ), and A 1g (675 cm À1 ) attributed to the characteristic vibrational modes of Fd-3 m space group (Figure 1 d). [22,38] It should be noted that the entropy-stabilized oxides contain Fe, Cr, Co, Ni, and Cu elements and their molar ratios are approximately 1: 1: 1: 1: 1, which is confirmed by energy dispersive X-ray (EDX) spectroscopy and inductively coupled plasma optical emission spectroscopy (ICP-OES) (Figure S1, Table S1 and S2). These results jointly validate that we have successfully synthesized spinel HEOs by the low-temperature plasma strategy.…”