Integrating photothermal and plasmonic catalysis induced by near-infrared light for efficient reduction of 4-nitrophenol

Abstract

The reduction of 4-nitrophenol (4-NP) into 4-aminophenol (4-AP) is an important reaction in both chemical manufacturing and environmental protection. The design of a highly active, multifunctional and reusable catalyst for efficient 4-NP decontamination/valorization is therefore crucial to bring in economic and societal benefits. Herein, we achieve an efficient plasmonic-photothermal catalyst of Pd nanoparticles by growing them on graphene-polyelectrolytes self-assembly nanolayers via an in situ green reduction approach using polyelectrolyte as the reductant. The as-fabricated catalyst shows high catalytic behaviors and good stability (maintained over 92.5 % conversion efficiency after ten successive cycles) for 4-NP reduction under ultra-low catalyst dose. The rate constant and turnover frequency were calculated at 0.197 min^-1 and 7.79 mmol g^-1 min^-1, respectively, which were much higher than those of most reported catalysts. Moreover, the as-prepared catalyst exhibited excellent photothermal conversion efficiency of ∼77 % and boosted 4-NP reduction by ∼2-fold under near-infrared irradiation (NIR). This study provides valuable insights into the design of greener catalytic materials and facilitates the development of multifunctional plasmonic-photothermal catalysts for diverse environmental, chemical, and energy applications using NIR.

Keywords: 4-NP reduction; Graphene-polyelectrolytes nanolayers; Near-infrared light; Pd nanoparticles; Plasmonic photothermal catalysis.