More-efficient water splitting utilizing heated-cooled active pure water with reduced hydrogen bonds
Year: 2026
Type: article
Abstract: Within the realm of renewable energy technologies—particularly those centered on hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs)—noble metals have long been regarded as the archetypal catalytic materials. In recent years, however, research efforts have pivoted toward earth-abundant, cost-effective catalysts featuring diverse compositional and structural motifs. A seminal development occurred in 2014 with the introduction of plasmon-activated water (PAW), an innovative system engineered through hot electron transfer (HET) from gold nanoparticles (AuNPs). In this review based on our published papers, we put forward an alternative paradigm aimed at enhancing HER and OER efficiencies by redirecting the focus onto water itself—specifically, a condensed water derived from Au-free processing of heated PAW containing trace amounts of Au. Relative to active PAW, this condensed form exhibits a diminished electron-doping character alongside more-pronounced disruption of hydrogen-bonding networks. Notably, its emergent properties are critically governed by the heating rate applied during PAW boiling. Analogous behaviors were observed in cooled active water, where the cooling rate during post-boiling treatment of deionized water (DIW) played a similarly decisive role. Remarkably, when employed in HER and OER applications, the heated-cooled active pure water—whether derived from PAW or DIW—consistently outperformed pristine DIW, a fact attributable to its distinctive features: reduced hydrogen-bond connectivity and a modified electron-doping state. Moreover, the latter property conferred upon the prepared active water a pronounced capacity for scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. Even after several days of aging, both the unique physicochemical characteristics and the corresponding electrochemical activities showed only marginal attenuation, underscoring its viability for real-world deployment. Collectively, our findings establish this stable active water as a promising green solvent platform capable of enabling more-efficient HERs and OERs in electrochemical systems.
Source: Applied Energy
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,430
OpenAlex ID: W7214539033