| abstract |
The present invention provides a visible light responsive photocatalyst powder that exhibits practical photocatalytic performance even in a daily indoor environment with low illuminance. Visible light responsive photocatalyst powder exhibits an organic gas decomposing ability that is nonlinear with respect to the amount of irradiated light under visible light having an illuminance in the range of 200 lx to 2500 lx. The visible light responsive photocatalyst powder has a gas concentration measured by flowing an acetaldehyde gas with an initial concentration of 10 ppm in a state where a 0.2 g sample is put in a flow-type apparatus, and the gas concentration before light irradiation is A, from light irradiation. The gas concentration at the time when 15 minutes or more have passed and when the gas is stable is defined as B, and the value calculated based on [Expression: (AB) / A × 100] from the gas concentration A and the gas concentration B is the gas decomposition rate (% ), For example, when irradiated with visible light having a wavelength of 380 nm or more and illuminance of 2500 lx, the gas decomposition rate is 20% or more. [Selection] Figure 1 |