2D/1D heterostructure of carbon nanotubes wrapping black phosphorus nanosheets with superior electrophilic property for improving oxygen evolution reaction

Black phosphorus (BP) is susceptible to oxidization under ambient conditions due to the exposed active lone pair electrons of P atoms, which will greatly decrease in activity and stability for oxygen evolution reaction (OER). Moreover, inferior adsorption property of BP partly restricts the OER activity. To solve these problems, BP is coupled with carbon nanotubes (CNTs) for constructing efficient metal-free BP/CNT (2D/1D) hetero-interface to transfer electrons and optimize the adsorption property. As is anticipated, characterization results reveal electrons transfer via this hetero-interface from BP NSs to CNTs occurs and alters interfacial electronic structure. Thus, this BP/CNT heterostructure displays high conductivity and superior electrophilicity. With this optimization of intrinsic electron-structure, the rate-determining step of electron transfer process is converted into chemical reaction process, and the activation energy towards OER dramatically is lowered. This effectively promotes the intrinsic activity and stability of BP/CNT hybrid. Moreover, here BP/CNT ratio, electrolytic time and electrolyte type are regulated to obtain best samples. The best BP/CNT prepared with TBACF3SO3 exhibits the lower overpotential of 35 mV than RuO2 at 10 mA cm−2. This work inspires us to design BP-based heterostructure and reveal the interfacial promotion effect for OER.