Fiber-in-tube RuxCr1−xOy as highly efficient electrocatalysts for pH-universal water oxidation via facile bubble desorption

Controlling atmospheric composition for thermal annealing yields diverse morphologies of bimetallic Ru–Cr oxides (Ru x Cr 1− x O y ). Ru x Cr 1− x O y _20 with fiber-in-tube structure excels in catalyzing pH-universal water oxidation, enabling easy bubble release.