Solar hydrogen and electricity are promising high energy-density renewable sources. Although photochemistry or photovoltaics are attractive routes, special challenge arises in sunlight conversion efficiency. To improve efficiency, various semiconductor materials have been proposed with selective sunlight absorption. Here, we reported a hybrid system synergizing photo-thermochemical hydrogen and photovoltaics, harvesting full-spectrum sunlight in a cascade manner. A simple suspension of Au-TiO₂ in water/methanol serves as a spectrum selector, absorbing ultraviolet-visible and infrared energy for rapid photo-thermochemical hydrogen production. The transmitted visible and near-infrared energy fits the photovoltaic bandgap and retains the high efficiency of a commercial photovoltaic cell under different solar concentration values. The experimental design achieved an overall efficiency of 4.2% under 12 suns solar concentration. Furthermore, the results demonstrated a reduced energy loss in full-spectrum energy conversion into hydrogen and electricity. Such simple integration of photo-thermochemical hydrogen and photovoltaics would create a pathway toward cascading use of sunlight energy.

太阳能氢和电是有前途的高能量密度可再生资源。尽管光化学或光伏技术是有吸引力的途径，但在日光转换效率方面仍存在特殊挑战。为了提高效率，已经提出了具有选择性的日光吸收的各种半导体材料。在这里，我们报告了一个混合系统，该系统可将光热化学氢和光伏电池协同工作，以级联方式收集全光谱阳光。Au-TiO _2的简单悬浮液在水/甲醇中的水用作光谱选择器，吸收紫外可见光和红外能量以快速产生光热化学氢。透射的可见光和近红外能量适合光伏带隙，并在不同的太阳能浓度值下保持了商用光伏电池的高效率。实验设计在12个太阳光下达到了4.2％的总效率。此外，结果表明减少了将全光谱能量转换为氢和电的能量损失。光热化学氢和光伏的这种简单整合将为级联使用太阳光能源创造一条途径。