Renewable fuels from concentrated solar power: towards practical artificial photosynthesis

Abstract

There is intense interest in the solar driven conversion of water to hydrogen as a means of achieving the sustainable generation of a practical fuel. It is widely considered that such "Artificial Photosynthesis" processes need to achieve an energy conversion efficiency exceeding 10 % to have practical impact. Although some solar--driven fuel generating systems have reached efficiencies as high as 18 %, they are often based on precious metal catalysts, or offer only limited stability.We describe here a system that utilises concentrated solar power, which is inexpensive to produce, and an electrolyser module based on Earth--abundant materials capable of operating under benign conditions. This system delivers the highest efficiency reported to date, in excess of 22 %. The electrolyser functions in electrolytes with pH values ranging from neutral to alkaline, including river water, allowing implementation in a variety of geographic locations. Testing over multiple diurnal cycles confirmed the long--term stability of performance. We also describe an analysis of the efficiency in terms of the critical cell--matching parameters and thereby understand the key directions for further optmisation. This simple and adaptable system addresses key criteria for the large--scale deployment of an artificial photosynthesis device.

Reduced Graphene Oxide-NiO/Ni Nanomembranes as Oxygen Evolution Reaction Electrocatalysts

“…It becomes interesting for us to study whether similar nickel oxide/nickel heterostructures could be grown on RGO. Furthermore, because nickel oxide/nickel can also serve as an active OER catalyst 13,[29][30][31][32][33] the OER properties of the nickel oxide/nickel heterostructures on RGO are worthy of further investigation.In this report, graphene oxide (GO) was used as a scaffold to support Ni-based nanoparticles and the resulting Ni nanocomposites were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM), and further tested as OER electrocatalysts. It was confirmed that nickel oxide/nickel heterostructures can be grown on RGO membranes.…”

“…It becomes interesting for us to study whether similar nickel oxide/nickel heterostructures could be grown on RGO. Furthermore, because nickel oxide/nickel can also serve as an active OER catalyst 13,[29][30][31][32][33] the OER properties of the nickel oxide/nickel heterostructures on RGO are worthy of further investigation.…”

Effects of nanostructure on clean energy: big solutions gained from small features

“…However, this system suffered from the lack of stability of the perovskite photovoltaic cells. More recently, another modular system that utilizes concentrated solar power and an electrode based on the earth-abundant material Ni showed a solar energy to fuel energy conversion efficiency of 22.4 % under various electrolyte conditions [27]. The overall performance of such a system can be optimized by choosing the right electrode material and particle size, as well as the right electrolyser conditions (e.g.…”

“…The overall performance of such a system can be optimized by choosing the right electrode material and particle size, as well as the right electrolyser conditions (e.g. electrolyte, operating temperature) [27].…”

The Technical and Energetic Challenges of Separating (Photo)Electrochemical Carbon Dioxide Reduction Products

“…A number of reviews have highlighted the importance of these technologies (e.g., Graves et al 2011;Newman et al, 2012;van der Giesen et al, 2014;Herron et al, 2015;Kumar et al, 2016). Promising progress has been demonstrated for solar H 2 from water splitting (Rongé et al, 2014;Ager et al, 2015;Bonke et al, 2015;Jia et al, 2016;Shi et al, 2016), though many challenges remain. However, carbon-based fuel production requires both the reduction of CO 2 and the oxidation of water, and is a far more challenging undertaking than the H 2 production alone.…”