Manipulation of the electronic state of Au to boost the catalytic efficiency of Au/polyaniline by doping engineering

Abstract

Polyaniline (PANI) support was doped by acids including HCl acid, 10-camphorsulfonic acid (CSA), thioglycollic acid (TA), and citric acid (CA), to modulate the environment of Au. The catalytic activities refer to the following sequence of Au/CA-PANI > Au/TA-PANI > Au/HCl-PANI ≈ Au/CSA-PANI > Au/EB-PANI toward the 4-nitrophenol (4-NP) reduction. It is found that a less positively charged Au surface can adsorb an appropriate 4-NP molecules and further increase the catalytic performance. The Au/CA-PANI with the lowest positively charged Au surface displayed the highest activity in 4-NP reduction with a reaction rate of 0.035 s−1 and a turnover frequency of 1997 h−1. The electronic state of Au likely played a decisive role for the catalytic activity differences. The readily microchemical environment tuning enabled for the accurate regulation of the electronic state of Au. This work provides a strategy for designing Au catalysts with an accurate electronic state surface.