Schottky construction of bimetallic Au-Cu alloy@TiO2 hollow nanoboxes embedded optical switch for enhancing photocatalytic and selective adsorption activities via one-pot deposition-precipitation strategy

Abstract

One-pot soft integration strategy based on wet chemistry via a simple in situ deposition-precipitation approach has been developed to fabricate series of bimetallic Au-Cu alloy@TiO2 hollow nanoboxes (THB) embedded optical switch. The bimetallic Au-Cu alloys were embedded into the nanodevice through Schottky junctions. This embedded optical switch could exhibit excellent photocatalytic performance. Under simulated sunlight irradiation, Au-Cu4:3 @THB nanodevice exhibited the photodegradation rate of RhB was of 99.4 % in 150 min, which was 3.0 times higher than that of THB. The oxidation rate of NO reached 27.0 %, 2.3 times that of THB. The enhanced photocatalytic activity could mainly be attributed to Au-Cu alloy SPR effects; the photoreactivity of the nanodevice was greatly improved after modification with bimetallic Au-Cu. Under dark conditions, the RhB adsorption rate of bimetallic Au-Cu4:3 @THB nanodevice reached 98.6 %, which was 6.1 times higher than that of THB. As the adsorption effect test of mixed dyes (MB/MO and RhB/MO), after 5 h of adsorption, the adsorption capacity of cationic dyes was 3.1 times that of anionic dyes, it was concluded that the bimetallic Au-Cu4:3 @THB optical switch had an excellent selective adsorption effect. This was due to the large surface area and mesoporous structure of the adsorbent, good electron transport structure, and the formation of a galvanic cell after adding dyes. This research provides a promising catalytic material with optical switch for environmental restoration and protection. It has broad application prospects in photocatalytic degradation, photocatalytic oxidation and adsorption of organic pollutants.