The rapid development of portable/wearable electronics proposes new demands for energy storage devices, which are flexibility, smart functions and long-time outdoor operation. Supercapacitors (SCs) show great potential in portable/wearable applications, and the recently developed flexible, smart and self-sustainable supercapacitors greatly meet the above demands. In these supercapacitors, conductive polymers (CPs) are widely applied due to their high flexibility, conductivity, pseudo-capacitance, smart characteristics and moderate preparation conditions. Herein, we’d like to introduce the CP-based flexible, smart and self-sustainable supercapacitors for portable/wearable electronics. This review first summarizes the flexible SCs based on CPs and their composites with carbon materials and metal compounds. The smart supercapacitors, i.e., electrochromic, electrochemical actuated, stretchable, self-healing and stimuli-sensitive ones, are then presented. The self-sustainable SCs which integrate SC units with energy-harvesting units in one compact configuration are also introduced. The last section highlights some current challenges and future perspectives of this thriving field.

Metal–organic frameworks (MOFs) have been identified as one of the promising electrocatalysts for the oxygen evolution reaction (OER). However, direct observation of the electrocatalytic behavior of MOF-based electrocatalysts remains extremely challenging, which is of great significance to understand their electrocatalytic mechanism. Herein, we developed a vertically oriented Ni-based MOF nanosheet array doped with 2.09 wt% Ce (denoted as Ce–NiBDC/OG). Ce–NiBDC/OG displayed a low overpotential of 265 mV to deliver a 10 mA cm⁻² current density for the OER. In situ spectroscopy and operando microscopy visualized the phase transformation behavior of Ce–NiBDC/OG to Ce-doped NiOOH induced by electrochemical activation, which was regarded as the real active site. Mechanistic studies revealed that, for the Ce–NiBDC/OG-derived catalyst, the doping of Ce species in NiOOH significantly increased the adsorption of *OH, and further reduced the energy barriers of the rate-determining step (*OH→*O).

The path to searching for sustainable energy has never stopped since the depletion of fossil fuels can lead to serious environmental pollution and energy shortages. Using water electrolysis to produce hydrogen has been proven to be a prioritized approach for green resource production. It is highly crucial to explore inexpensive and high‐performance electrocatalysts for accelerating hydrogen evolution reaction (HER) and apply them to industrial cases on a large scale. Here, we summarize the different mechanisms of HER in different pH settings and review recent advances in non‐noble‐metal‐based electrocatalysts. Then, based on the previous efforts, we discuss several universal strategies for designing pH‐independent catalysts and show directions for the future design of pH‐universal catalysts.