Photoelectrons could initiate excited-state chemistry to enable low-temperature reactions which are kinetically prohibited at ground state. Triggering more photoelectrons is considered as the key to implement solar advantage for facile catalysis, which is usually realized via concentrating photo-intensity. However, this method suffers from the photo-saturation effect when the light intensity reaches a threshold. In this paper, Joel and co-authors demonstrate a counter-intuitive waveguide strategy to surmount the photo saturation of indium oxide catalyst by distributing, instead of concentrating, the light intensity. See full story at Nature Communications.