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

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 & mu;g cm-2. Moreover, it showed excellent volatile organic compound removal performance.

Automated summary

In order to overcome the narrow absorption bandwidth of plasmonic metal materials, a plasmonic nanocomposite Au NR@Cu7S4 was constructed by growing a copper sulfide (Cu7S4) shell on a gold nanorod (Au NR) core. This nanocomposite exhibited broad and intense absorption of solar radiation due to the integration of individually visible (Au NR) and near-infrared (Cu7S4) plasmons, with further enhancement from the coupling of these two plasmons. Unlike aggregating plasmonic metal nanoparticles, this strategy avoids the trade-off between the breadth and intensity of absorption. The Au NR@Cu7S4-impregnated hydrogel achieved an evaporation rate of 2.35 kg m- 2 h-1 under 1 sun illumination, even with a low areal density of gold (28 μg cm-2). Moreover, it showed excellent performance in volatile organic compound removal.