Abstract In this study, metal-organic-framework (MOF) derived porous NiO hollow spheres and flowers were obtained using facile solvothermal synthesis and heat treatment. After pyrolyzing, the flower like and hollow spherical like morphology of NiO nanoparticles was successfully inherited from the initial MOF-based templates. The electrochemical studies demonstrated that the porous NiO hallow spheres unveiled a better supercapacitive performance (specific capacitance (Cs) = 1058 F g−1 at current density (j) = 2 A g−1) and oxygen evolution reaction (OER) catalytic activity (overpotential (ɳ) = 323 mV) compared to porous NiO flowers (Cs = 857 F g−1 at j = 2 A g−1 and ɳ = 346 mV). Moreover, excellent capacity retention of over 93% was obtained in porous NiO-hs nanoparticles even after 5000 cycles. The fabricated NiO//Fe2O3 asymmetric supercapacitor delivered an energy density (E) of 35.75 W h Kg−1 under power density (P) of 780 W kg−1 and showed promising stability over 3000 cycles. Considering the ease of preparation and high catalytic activity and supercapacitive performance, these prous NiO hallow structures can be considered as a potential electrode material for next generation energy storage devices and OER catalysts.

中文翻译：

---

用于析氧反应和超级电容器的高多孔金属有机框架衍生的 NiO 空心球和花

摘要 在本研究中，通过简单的溶剂热合成和热处理，获得了金属有机骨架 (MOF) 衍生的多孔 NiO 空心球和花。热解后，NiO纳米颗粒的花状和空心球状形态成功地继承了最初的基于MOF的模板。电化学研究表明，多孔 NiO 空心球具有更好的超级电容性能（电流密度 (j) = 2 A g-1 下的比电容 (Cs) = 1058 F g-1）和析氧反应 (OER) 催化活性（过电位 (ɳ) = 323 mV) 与多孔 NiO 花（Cs = 857 F g-1 在 j = 2 A g-1 和 ɳ = 346 mV）相比。此外，即使在 5000 次循环后，多孔 NiO-hs 纳米颗粒也获得了超过 93% 的优异容量保持率。所制造的 NiO//Fe2O3 非对称超级电容器在 780 W kg-1 的功率密度 (P) 下提供了 35.75 W h Kg-1 的能量密度 (E)，并且在 3000 次循环中表现出良好的稳定性。考虑到易于制备、高催化活性和超级电容性能，这些具有优势的 NiO 空心结构可被视为下一代储能装置和 OER 催化剂的潜在电极材料。