Polypyrrole/cadmium sulfide hollow fiber with high performance contaminant removal and photocatalytic activity fabricated by layer-by-layer deposition and fiber-sacrifice template approach

A recyclable polypyrrole (PPy)/cadmium sulfide (CdS) hollow fiber photocatalyst was innovatively fabricated for solving the loss issue of the current powder-form photocatalyst in slurry system. Core-sheath structure CdS/polyacrylonitrile (PAN) fiber was prepared via successive ionic layer adsorption and reaction (SILAR) method on the surface of PAN fiber. PPy was further deposited on the CdS/PAN fiber by vapor deposition polymerization. After the removal of interior PAN template, PPy/CdS hollow fiber was yielded. The hollow structure of PPy/CdS hollow fiber was confirmed by morphology observation. The resulting PPy/CdS hollow fiber presents low energy band gaps of 1.9 eV, which accounts for enhanced visible light photocatalytic activity after PPy deposition. PPy/CdS hollow fiber shows good dye removal efficiency of 73.06 wt% (dosage of the product as low as 5 mg.10 mL(-1)), and praiseworthy H-2 production rate up to 269.7 mu mol.g(-1).h(-1). PPy/CdS hollow fiber maintained high and sustainable photocatalytic activity compared to CdS/PAN fiber after 8 cycles, indicating that PPy effectively improved the stability of CdS. Here, PPy plays key synergistic role in photocatalysis of PPy/CdS hollow fiber for the promotive and protective effects based on the actual photocatalytic performance and inductively coupled plasma optical emission spectrometer (ICP-OES) results. Compared with nano-sized photocatalysts, the fiber-formed PPy/CdS hollow fiber is highly bulky and easy to recycle. PPy/CdS hollow fiber has great potential for scale-up in industrial application because of its excellent grabbing ability and degradation to contaminants, and ease of disposal. (C) 2019 Elsevier Inc. All rights reserved.