In this comprehensive review, recent progress and developments on perfluorinated sulfonic-acid (PFSA) membranes have been summarized on many key topics. Although quite well investigated for decades, PFSA ionomers’ complex behavior, along with their key role in many emerging technologies, have presented significant scientific challenges but also helped create a unique cross-disciplinary research field to overcome such challenges. Research and progress on PFSAs, especially when considered with their applications, are at the forefront of bridging electrochemistry and polymer (physics), which have also opened up development of state-of-the-art in situ characterization techniques as well as multiphysics computation models. Topics reviewed stem from correlating the various physical (e.g., mechanical) and transport properties with morphology and structure across time and length scales. In addition, topics of recent interest such as structure/transport correlations and modeling, composite PFSA membranes, degradat...

New Insights into Perfluorinated Sulfonic-Acid Ionomers

Solar water splitting is a promising approach to transform sunlight into renewable, sustainable and green hydrogen energy. There are three representative ways of transforming solar radiation into molecular hydrogen, which are the photocatalytic (PC), photoelectrochemical (PEC), and photovoltaic–electrolysis (PV–EC) routes. Having the future perspective of green hydrogen economy in mind, this review article discusses devices and systems for solar-to-hydrogen production including comparison of the above solar water splitting systems. The focus is placed on a critical assessment of the key components needed to scale up PEC water splitting systems such as materials efficiency, cost, elemental abundancy, stability, fuel separation, device operability, cell architecture, and techno-economic aspects of the systems. The review follows a stepwise approach and provides (i) a summary of the basic principles and photocatalytic materials employed for PEC water splitting, (ii) an extensive discussion of technologies, procedures, and system designs, and (iii) an introduction to international demonstration projects, and the development of benchmarked devices and large-scale prototype systems. The task of scaling up of laboratory overall water splitting devices to practical systems may be called “an artificial photosynthetic leaf-to-farm challenge”.

Toward practical solar hydrogen production - an artificial photosynthetic leaf-to-farm challenge.

A widely used term, “photocatalysis”, generally addresses photocatalytic (energetically downhill) and photosynthetic (energetically uphill) reactions and refers to the use of photonic energy as a driving force for chemical transformations, i.e., electron reorganization to form/break chemical bonds. Although there are many such important reactions, this contribution focuses on the fundamental aspects of photocatalytic water splitting into hydrogen and oxygen by using light from the solar spectrum, which is one of the most investigated photosynthetic reactions. Photocatalytic water splitting using solar energy is considered to be artificial photosynthesis that produces a solar fuel because the reaction mimics nature’s photosynthesis not only in its redox reaction type but also in its thermodynamics (water splitting: 1.23 eV vs glucose formation: 1.24 eV). To achieve efficient photocatalytic water splitting, all of the parameters, though involved at different time scales and spatial resolutions, should be op...

http://pubs.acs.org/doi/pdf/10.1021/acscatal.7b02662

Photocatalytic Water Splitting: Quantitative Approaches toward Photocatalyst by Design

Phosphorus is a nonmetal with several allotropes, from the highly reactive white phosphorus to the thermodynamically stable black phosphorus (BP) with a puckered orthorhombic layered structure. The bulk form of BP was first synthesized in 1914, but received little attention until it was rediscovered in 2014 as a member of the new wave of 2D layered nanomaterials. BP can be exfoliated to a single sheet that acts as a semiconductor with a tunable direct band gap, a high carrier mobility at room temperature, and an in-plane anisotropy. The development of BP applications is hampered by surface degradation, thus efforts to achieve effective BP passivation are ongoing, such as its integration in van der Waals heterostructures. BP has been tested as a novel nanomaterial in batteries, transistors, sensors, and photonics. This Review begins with the origin of the BP story, following the path from a bulk material to modern few/single layers. The physical and chemical properties are summarized, and the state-of-the-art of BP applications highlighted.

Black Phosphorus Rediscovered: From Bulk Material to Monolayers

This work is a review of the recent trends in the photoelectrocatalytic conversion of solar energy into electricity or hydrogen. It focuses on photocatalytic fuel cells and photoelectrocatalytic water splitting systems and presents both the basic principles and the design of devices. It includes a broad review of materials employed for the construction of photoanodes, photocathodes and tandem cells and highlights the related research fields which are expected to be of interest in the near future. The review is intended to become a basic manual for new adepts to the field and at the same time a handy reference to experienced researchers.

Review of recent trends in photoelectrocatalytic conversion of solar energy to electricity and hydrogen

An integrated cell for the solar-driven splitting of water consists of multiple functional components and couples various photoelectrochemical (PEC) processes at different length and time scales. The overall solar-to-hydrogen (STH) conversion efficiency of such a system depends on the performance and materials properties of the individual components as well as on the component integration, overall device architecture, and system operating conditions. This Review focuses on the modeling- and simulation-guided development and implementation of solar-driven water-splitting prototypes from a holistic viewpoint that explores the various interplays between the components. The underlying physics and interactions at the cell level is are reviewed and discussed, followed by an overview of the use of the cell model to provide target properties of materials and guide the design of a range of traditional and unique device architectures.

/pdf/modeling-simulation-and-implementation-of-solar-driven-water-10wh5i2prc.pdf

Yi Kai Chen

Papers

Modeling, Simulation, and Implementation of Solar-Driven Water-Splitting Devices.

Effect of soaking time on targets and bycatch species catch rates in fish and crab trap fishery in the southern East China Sea