Formaldehyde-purifying air conditioner with integrated gas-phase photoelectrocatalytic system.

Developing an efficient and economical indoor air purification system for catalytic decomposition of formaldehyde is of great significance. In this work, an indoor air conditioner capable of purifying formaldehyde was designed by directly integrating defective WO3/TiO2 nanotube catalytic fin, with both thermal conductivity and gas-phase photoelectrocatalytic (GPEC) properties, onto the condenser component. The electrochemical treatment of the catalytic fin introduced a substantial number of oxygen vacancies, resulting in a significant increase in carrier concentration and mobility to the semi-metallic level. As a result, under illumination and a tiny voltage input of 1.0-2.5 V, effective photogenerated carrier separation occurred within the catalytic fins, enabling the air conditioner to achieve remarkable formaldehyde removal performance at a clean air delivery rate of 2.7 m3/h by replacing only 15 % of the original fins on the condenser. This technology integration avoids the extra space occupation and eliminates secondary pollution associated with the replacement of consumables or desorption of saturated adsorbents in traditional filtration or adsorption systems, and significantly improves catalytic efficiency without the need for significant modifications to air conditioning production lines or molds, making large-scale deployment feasible.