Abstract-Hydrogengas has been shown to photocatalytically generated from pure water. With saltwater comprising 93% of the earth's water reservoir, methods to produce hydrogen from seawater minus the expensive water purification are desired. Cd 0.8 Zn 0.2 S has been proven as an effective photocatalyst for hydrogen production but it remains to be tested in seawater. This study provides proof of concept for hydrogen production from seawater using fresh and reused Cd 0.8 Zn 0.2 S upon irradiation with visible light and with the addition of sulfide/sulfite as sacrificial agents. The post-usage characteristics of Cd 0.8 Zn 0.2 S catalyst were investigated using SEM and FTIR. The rate of hydrogen gas production from seawater was up to six times faster than in distilled and simulated seawater for both fresh and reused catalyst. Reused catalyst showed reduced rates of gas accumulation. Catalysts exposed to non-distilled water showed marked changes in their SEM appearance and their spectral transmittance.