Improvement of formaldehyde sensitivity of ZnO nanorods by modifying with Ru(dcbpy)2(NCS)2

The ZnO nanorods (diameter of 40 nm and 100 nm) were modified with Ru(dcbpy)2(NCS)2 (RuN3), and their responses to formaldehyde were measured at room temperature. All the results showed that the responses to formaldehyde of modified ZnO were higher than that of bare ZnO; especially the responses of modified ZnO nanorods with diameter of 40 nm–5 ppm formaldehyde was about 200% higher than that of bare ZnO. The UV–vis absorption spectrum and transient photovoltage analysis showed that the high responses of modified ZnO mainly arose from the strong photocatalytic oxidizing effect induced by the increasing of the absorption and photo-generated electron–hole separation. Our results demonstrate that the modification of RuN3 is a promising approach on improving the formaldehyde responses of ZnO nanorods.