Figure 2: Photocatalytic reaction apparatus, A: LED lamp ( , and 390 nm), B: glass holder, C: catalyst (20 × 16 × 0.5 mm), D: colorless and transparent quartz cover, E: sealed opaque reactor (plastic, 373 cm3), F: 2 ppm standard NO gas (flow rate: 100 mL/min), G: dried air (flow rate: 100 mL/min), H: gas mixer, I, J, K: three-way cock, L: NOx analyzer (Yanaco, ECL-88A).