Plasmonic metal/doped-semiconductor nanocomposites for high-efficiency solar-driven clean water production

Abstract

Despite their strong light absorption capacity, the narrow absorption bandwidth of plasmonic metal materials has impeded their application in solar-driven freshwater production. To address this limitation, we grew copper sulfide (Cu7S4) shell on gold nanorod (Au NR) core to construct a plasmonic nanocomposite Au NR@Cu7S4, which exhibited broad and intense absorption of solar radiation due to the integration of their individually visible (Au NR) and near-infrared (Cu7S4) plasmons, with this absorption being further broadened and enhanced by the coupling of these two plasmons. This strategy is conceptually distinct from aggregating plasmonic metal nanoparticles, which is subject to a trade-off between the breadth and intensity of their absorption. The Au NR@Cu7S4-impregnated hydrogel delivered an evaporation rate of 2.35 kg m−2 h−1 under 1 sun illumination despite having a Au areal density of only 28 μg cm−2. Moreover, it showed excellent volatile organic compound removal performance.