Metal oxides are a promising catalyst for photoelectrochemical (PEC) water splitting to produce hydrogen as alternative energy. However, their effectiveness is restricted at low voltage. A research team has successfully mediated the poor charge carrier transport at low voltage by adding phosphorus to a metal oxide catalyst, which reduced energy losses during water splitting. The findings offer a potential option for achieving carbon neutrality.Metal oxides are a promising catalyst for photoelectrochemical (PEC) water splitting to produce hydrogen as alternative energy. However, their effectiveness is restricted at low voltage. A research team has successfully mediated the poor charge carrier transport at low voltage by adding phosphorus to a metal oxide catalyst, which reduced energy losses during water splitting. The findings offer a potential option for achieving carbon neutrality.