Electrocatalytic reduction of bromate based on Pd nanoparticles uniformly anchored on polyaniline/SBA-15. (December 2015)

• Record Type: Journal Article
• Authors: Sun, Chencheng; Deng, Ning; An, Hao; Cui, Hao; Zhai, Jianping
• Is Part Of: Chemosphere. Volume 141(2015)
• Page Start: 243
• Page End: 249
• Publication Date: 2015-12
• Subjects: Bromate -- Palladium-based electrocatalyst -- Electrocatalytic reduction -- Cyclic voltammetry -- Amperometric measurement; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2015.08.004
• Languages: English
• ISSNs: 0045-6535

Abstract

Graphical abstract: Highlights: Pd-NPs/PANI/SBA-15 electrocatalyst is synthesized for BrO3 − elimination. Ultrafine Pd-NPs of average diameter 3.1 nm are anchored on PANI/SBA-15. Pd-NPs/PANI/SBA-15 shows remarkable electrocatalytic activity and stability. The BrO3 − electroreduction peak occurs between 0.12 and −0.22 V (vs. SCE). Pd-NPs/PANI/SBA-15 is a good candidate for BrO3 − amperometric sensor. Abstract: A nano-composite electrocatalyst of Pd nanoparticles (Pd-NPs) anchored on polyaniline (PANI) supported by mesoporous SBA-15 (Pd-NPs/PANI/SBA-15), was synthesized using an in situ chemical method. Transmission electron microscopy showed that the Pd-NPs were homogeneously dispersed. Fourier-transform infrared and X-ray photoelectron spectroscopies confirmed that the Pd-NPs in the metallic state (Pd 0 ) were predominantly immobilized on nitrogen sites in the PANI chains. The electrochemical performance of Pd-NPs/PANI/SBA-15 for electrocatalytic reduction of bromate (BrO3 − ) in an acidic medium was investigated by cyclic voltammetry (CV) and amperometric measurement. The reduction peak in the CV curves in the region 0.12 to −0.22 V (vs. SCE) corresponded to response of BrO3 − electroreduction, and the reduction peak current was well fitted linearly to the BrO3 − concentration. It is proposed that the bromate ions diffuse to the Pd-NPs active sites and then the electrocatalytic reduction occurred with the H + doped in PANI. Furthermore, by amperometric measurement, Pd-NPs/PANI/SBA-15 showed relatively high sensitivity with respect to BrO3 − concentration in the range of 8 μmol L −1 to 40 mmol L −1 . Continuous CV for 200 cycles proved that Pd-NPs/PANI/SBA-15 had excellent electrocatalytic stability. These results show that Pd-NPs/PANI/SBA-15 is effective for electrocatalytic reduction of BrO3 − and has great potential for the fabrication of BrO3 − electrochemical sensor.