Enhanced solar energy absorption on nitrogen-doped carbon nanotubes decorated with gold-palladium bimetallic nanoparticles

Abstract

Gold-palladium alloy nanoparticles decorated on nitrogen-doped carbon nanotubes (Au-Pd/N-CNT) were prepared by using polyethylene imine reduction method. Polyethylene acts as not only a stabilizing agent, but also a reducing agent, leading to nucleation and growth of nanoparticles on the N-CNT surfaces. All the N-CNT-based nanofluids show broadband absorption across the visible region and near infrared region. The Au-Pd/N-CNT nanofluids absorb more solar irradiation compared with monometallic Pd/N-CNT or Au/N-CNT nanofluid. The photo-thermal conversion efficiency of Au-Pd /N-CNT nanofluids is 62.3%, compared with 53.3% and 57% for Pd/N-CNT and Au/N-CNT, respectively. This enhancement was mainly due to the synergetic effects of N-CNT and Au-Pd alloy nanoparticles.