A hierarchical S-scheme heterojunction photocatalyst was fabricated through the in situ growth of BiOBr nanosheets on microtubular C₃N₄, which demonstrates excellent photocatalytic activity for converting CO₂ into CO under visible light irradiation.

Manganese oxide (MnO₂) has long been investigated as a pseudo-capacitive material for fabricating fiber-shaped supercapacitors but its poor electrical conductivity and its brittleness are clear drawbacks. Here we electrochemically insert nanostructured MnO₂domains into continuously interconnected carbon nanotube (CNT) networks, thus imparting both electrical conductivity and mechanical durability to MnO₂. In particular, we synthesize a fiber-shaped coaxial electrode with a nickel fiber as the current collector (Ni/CNT/MnO₂); the thickness of the CNT/MnO₂hybrid nanostructured shell is approximately 150 μm and the electrode displays specific capacitances of 231 mF cm⁻¹. When assembling symmetric devices featuring Ni/CNT/MnO₂coaxial electrodes as cathode and anode together with a 1.0 M Na₂SO₄aqueous solution as electrolyte, we find energy densities of 10.97 μWh cm⁻¹. These values indicate that our hybrid systems have clear potential as wearable energy storage and harvesting devices.