Achieving water-floatable photocatalyst on recycled bamboo chopsticks.

ABSTRACT

Disposable bamboo chopsticks (DBCs) are difficult to recycle, which inevitably cause secondary pollution. Based on energy and environmental issues, we propose a facile strategy to fabricate floatable photocatalyst (fPC) coated onto DBCs, which can be flexibly used in water purification. The photocatalyst of titania and titanium carbide on bamboo (TiO2/TiC@b) was successfully constructed from TiC-Ti powders and DBCs using a coating technique followed heat treatment in carbon powder, and the fPC exhibited excellent photocatalytic activity under visible light irradation. The analysis results indicate that rutile TiO2 forms on TiC during heat treatment, achieving a low-density material with an average value of approximately 0.5233 g/cm3. The coatings of TiO2/TiC on the bamboo are firm and uniform, with a particle size of about 20-50 nm. XPS results show that a large amount of oxygen vacancies is generated, due to the reaction atmosphere of more carbon and less oxygen, further favoring to narrowing the band gap of TiO2. Furthermore, TiO2 formed on residual TiC would induce the formation of a heterojunction, which effectively inhibits the photogenerated electron-hole recombination via the charge transfer effect. Notably, the degradation of dye Rhodamine B (Rh.B) is 62.4% within 3 h, while a previous adsorption of 36.0% for 1 h. The excellent photocatalytic performance of TiO2/TiC@b can be attributed to the enhanced reaction at the water/air interface due to the reduced light loss in water, improved visible-light response, increased accessible area and charge transfer effect. Our findings show that the proposed strategy achieves a simple, low-cost, and mass-producible method to fabricate fPC onto the used DBCs, which is expected to applied in multiple fields, especially in waste recycling and water treatment.