Prof. Can Li’s group has recently made progress on photocatalytic overall water splitting. They reported that a tuneable α—β surface phase junction on Ga2O3 can significantly improve photocatalytic overall water splitting into H2 and O2 over individual α-Ga2O3 or β-Ga2O3 surface phases. The enhanced photocatalytic performance is shown to be due to efficient charge separation and transfer across the α–β phase junction. The phase-junction approach will open new avenues for the development of efficient photocatalysts for overall water splitting, as well as photoelectronic devices. （Angew. Chem. Int. Ed., DOI: 10.1002/anie.201207554，Hot Paper）