Investigation of polyethylene glycol (PEG) assisted solvothermal synthesis of CuCoO₂ nanosheets for efficient oxygen evolution reaction

Abstract

Water splitting to produce hydrogen is known as an effectively alleviate the energy crisis, but slow kinetics of oxygen evolution reaction (OER) has been seriously restricting the development of water...

The interaction of carbon nanotubes (CNTs) with CuCoO2 nanosheets promotes structural modification and enhances their OER performance

“…Furthermore, the overpotential (at 10 mA cm −2 ) and Tafel slope of Ni@CCO/50CNT are close to or even better than those of other non-noble metal oxide catalysts (Fig. 4d and Table S3 †), such as delafossite oxides, including Fe-CuCoO 2 (η 10 = 369 mV, Tafel slope = 69 mV dec −1 ), 15 CuCoO 2 (η 10 = 378 mV, Tafel slope = 85 mV dec −1 ), 16 and CuGaO 2 (η 10 = 400 mV, Tafel slope = 61 mV dec −1 ); 55 60 and CoSnS@CNT (η 10 = 350 mV, Tafel slope = 75 mV dec −1 ). 61 The electrochemically active surface area (ECSA) is proportional to the density of the active sites, which can be used to evaluate the number of active sites.…”

“…3a, the peaks observed at 931.94 eV and 932.62 eV correspond to Cu + 2p 3/2 and Cu 2+ 2p 3/2 , respectively, while the peaks at 951.69 eV and 952.98 eV are assigned to Cu + 2p 1/2 and Cu 2+ 2p 1/2 . 16 The spectral analysis of Cu 2p reveals that Cu predominantly exists in a monovalent state within CuCoO 2 . Fig.…”

“…To address these issues, our research group has focused on modifying CuCoO 2 nanocrystals and enhancing their OER performance. [8][9][10][11][12][13][14][15][16] By the utilization of metal-organic framework (MOF) materials such as Cu-BTC and ZIF-67 in the hydrothermal reaction precursors, we have successfully increased the specific surface area of CuCoO 2 nanocrystals, resulting in an exceptional OER performance (with a low overpotential of 364.7 mV at 10 mA cm −2 , i.e., η 10 = 364.7 mV). 13 Additionally, we employed polyethylene glycol (PEG) as a template agent to synthesize CuCoO 2 nanocrystals with a lateral size of 150 nm and a thickness of 13 nm.…”

“…The decrease of size reduces the overpotential of CuCoO 2 from 415 mV to 378 mV at 10 mA cm −2 . 16 Accordingly, our research group has conducted extensive systematic studies on the utilization of CuCoO 2 catalysts in water splitting. However, similar to many other non-noble metal catalysts currently available, the OER performance of CuCoO 2 still falls short of that of noble metal catalysts, such as RuO 2 and IrO 2 .…”

“…In this work, the effects of carboxylated multi-walled CNTs on the structure and OER properties of CuCoO 2 nanocrystals were studied on the basis of our previous work. 15,16 Multi-walled CNTs are chosen because of their good stability in the OER process and low cost. At the same time the inner walls remain intact and conductive after the outermost layers of multi-walled CNTs are functionalized.…”