The preparation of low-cost and efficient bifunctional catalysts towards water splitting is essential for the production of clean H2 energy. Herein, a hierarchical Co3O4-decorated CuO–Cu2O nanorod core–shell structure was in situ grown on a Cu foam (denoted as CuOx@Co3O4 NRs/CF) and investigated as a bifunctional catalyst for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solution. Benefiting from its large electrochemical surface area and the synergetic effects between the CuOx core and Co3O4 shell, CuOx@Co3O4 NRs/CF exhibited considerable catalytic activity, which resulted in a small overpotential of 240 mV for the OER and 242 mV for the HER at a current density of 50 mA cm−2, along with low Tafel slopes of 46 and 61 mV dec−1, respectively. Remarkably, CuOx@Co3O4 NRs/CF could continuously produce O2 or H2 for at least 24 h with negligible decline in catalytic activity, and it gave rise to high faradaic efficiencies of 99.7% and 96.4% for the OER and HER, respectively. The electrochemical performance of CuOx@Co3O4 NRs/CF was dramatically improved as compared to those of its CuOx NRs/CF counterpart and also most reported Cu-based water splitting electrocatalysts.
Pengcheng Jiao,Xiutao Yang,Yuying Wang,Hongwen Yu,Ying Zeng,Guopeng Zhu,Chunhui Wang,Deming Han
Rational design on the microstructure and chemical composition of transition metal-based electrode materials is critical for boosting electrochemical glucose detection. In this work, the hollow heterostructured CuO x @Co 3 O 4 nanotube arrays on Cu foam (CuO x @Co 3 O 4 NTAs/CF) were fabricated. Coupling Co 3 O 4 nanoparticles on CuO x nanotube modulates the electronic structure by heterostructure, enhancing charge transfer during electrocatalytic glucose oxidation. Moreover, the unique hierarchical tubular core-shell structure guarantees abundant well-distributed active sites and rapid pathways for glucose and electrolyte diffusion. Beneficial from the advanced structure, the sensor fabricated with CuO x @Co 3 O 4 NTAs/CF possesses a high sensitivity of 23347.4 μA mM⁻¹ cm⁻² at linear range of 10-527 μM and low limit of detection of 0.56 μM (S/N=3). In addition, the outstanding selectivity, reproducibility and long-term stability (94.5 % for 30 days) as well as good recovery rate in artificial saliva, sweat, and human serum samples are also accessible advantages for our fabricated sensor. The excellent sensing performance of CuO x @Co 3 O 4 NTAs/CF demonstrates its potential application for electrochemical glucose detection.
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