To enhance photocatalytic water splitting, various oxidizing sacrifice agents (OSA) have been added to the system in order to scavenge the coproduced O-2, and, thus, to hinder the reverse reactions. In the aim of achieving carbon-neutral photocatalytic water splitting, nonfood hydrocarbons of castor-and jojoba-oils were evaluated as OSA. Moreover, various surfactants were tested as emulsifiers for W/O binary solution for promoting photocatalytic water splitting rate. Among the OSA used, the castor-oil was found to be more suitable candidate compared to jojoba-oil, which was attributed to its smaller carbon chain numbers of mainly 18. Without surfactants, around 20 vol %-castor-oil aqueous binary solution with TiO2/Pt(0.10 wt %) provided the highest water splitting rate of about 30 mL-H2(/)(m(2).h). Among tested surfactants, liquid-detergent was the best due to its optical transparency. 40 vol %- or 60 vol %-castor-oil emulsion with a drop of liquid-detergent resulted in a water splitting rate of 125 mL-H-2/(m(.)(2)h), which was four times greater that the aforementioned highest value. (C) 2010 American Institute of Chemical Engineers AIChE J, 57: 2237-2243, 2011