Gokhale Devashish, Jain Prashant K, Su Xiao
Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Nat Commun. 2025 Aug 7;16(1):7284. doi: 10.1038/s41467-025-61879-8.
Photoelectrochemical systems harness onsite solar energy to drive chemical processes, enabling improvements in sustainability and decarbonization. Photoelectrochemical systems have been extensively studied for reactions such as hydrogen production; however, competitive costs are difficult to attain due to the limited solar efficiency of low-cost photoelectrochemically stable materials. Building on this premise, we propose that applications that do not require high solar-efficiency materials to deliver meaningful throughput are needed for photoelectrochemical systems. Using rigorous thermodynamic modeling grounded in experimental data, we demonstrate the existence of such applications in chemical separations, which comprise processes critical to tackling global challenges in water treatment and resource recovery. Operating domains and scales at which photoelectrochemical separations utilizing low solar efficiency materials can be practical and cost-competitive against modular photovoltaic-electrochemical systems are identified. This study demonstrates that photoelectrochemical separations have a design space broader than classical applications, and establishes thermodynamic limits and targets, paving the way for real-world impact with photoelectrochemical technology.
光电化学系统利用现场太阳能来驱动化学过程，从而实现可持续性和脱碳方面的改善。光电化学系统已针对诸如制氢等反应进行了广泛研究；然而，由于低成本光电化学稳定材料的太阳能效率有限，难以实现具有竞争力的成本。基于这一前提，我们提出光电化学系统需要那些不需要高太阳能效率材料就能实现有意义产量的应用。利用基于实验数据的严格热力学模型，我们证明了在化学分离中存在此类应用，而化学分离包括应对水处理和资源回收方面全球挑战的关键过程。确定了利用低太阳能效率材料的光电化学分离在实际应用中能够实用且相对于模块化光伏 - 电化学系统具有成本竞争力的操作范围和规模。本研究表明，光电化学分离的设计空间比传统应用更广阔，并确立了热力学极限和目标，为光电化学技术产生实际影响铺平了道路。
