Enhancement of photocatalytic activity of UV/photocatalysis was carried out to oxidize the gaseous H2S in a tubular reactor coated with photocatalyst of sol type TiO2. EtOH was used as the standard material to select the photocatalyst, and it was confirmed that the reactor activity was dependent on the coated surface characteristics. The selected photocatalytic reactor, which coated with STS-01, showed about 80% conversion when the gas linear velocity was 0.01 m/s and relative humidity was 40%. However, the conversion level of the reaction decreased significantly with increasing gas linear velocity. Pt was loaded on the photocatalyst to enhance and maintain the performance of the reactor, which enhanced the conversion level of H2S more than 95% under the same experimental condition.