Dischargeable nickel matrix charges iron species for oxygen evolution electrocatalysis

Stable selenium nickel-iron electrocatalyst for oxygen evolution reaction in alkaline and natural seawater

The development of efficient and stable catalysts for oxygen evolution reaction (OER) in seawater presents a major challenge for hydrogen production through water electrolysis. In this work, we present a stable NiFe foam catalyst with a Se-doped Ni/Fe oxide surface prepared through a combination of chemical vapor deposition and electrochemical exfoliation. This method effectively modifies the surface of the commercial NiFe foam to a rough and stable Se-doped Ni/Fe oxide surface, displaying exceptional OER performance in both freshwater and seawater with more than 54 days stability in natural seawater. Characterizations reveal Ni-Se doped Fe oxide surface, with subsurface layers consisting of Ni alloyed with a moderate concentration of Fe, optimizes the adsorption free energy of oxygen-containing intermediates. Our results demonstrate a surface engineering approach to activate NiFe foam as a robust OER catalyst for seawater electrolysis, which is beneficial for the hydrogen economy and for the environment.

Artificial Photosynthesis: Current Advancements and Future Prospects

Artificial photosynthesis is a technology with immense potential that aims to emulate the natural photosynthetic process. The process of natural photosynthesis involves the conversion of solar energy into chemical energy, which is stored in organic compounds. Catalysis is an essential aspect of artificial photosynthesis, as it facilitates the reactions that convert solar energy into chemical energy. In this review, we aim to provide an extensive overview of recent developments in the field of artificial photosynthesis by catalysis. We will discuss the various catalyst types used in artificial photosynthesis, including homogeneous catalysts, heterogeneous catalysts, and biocatalysts. Additionally, we will explore the different strategies employed to enhance the efficiency and selectivity of catalytic reactions, such as the utilization of nanomaterials, photoelectrochemical cells, and molecular engineering. Lastly, we will examine the challenges and opportunities of this technology as well as its potential applications in areas such as renewable energy, carbon capture and utilization, and sustainable agriculture. This review aims to provide a comprehensive and critical analysis of state-of-the-art methods in artificial photosynthesis by catalysis, as well as to identify key research directions for future advancements in this field.

Durable Nickel-Iron (Oxy)hydroxide Oxygen Evolution Electrocatalysts through Surface Functionalization with Tetraphenylporphyrin

NiFe-based oxides are one of the best-known active oxygen evolution electrocatalysts. Unfortunately, they rapidly lost performance in Fe-purified KOH during the reaction. Herein, tetraphenylporphyrin (TPP) was loaded on a catalyst/electrolyte interface to alleviate the destabilization of NiFe (oxy)hydroxide. We propose that the degradation occurs primarily due to the release of thermodynamically unstable Fe. TPP acts as a protective layer and suppresses the dissolution of hydrated metal at the catalyst/electrolyte interface. In the electric double layer, the nonpolar TPP layer on the NiFe surface also invigorates the redeposition of the active site, Fe, which leads to prolonging the lifetime of NiFe. The TPP-coated NiFe was demonstrated in anion exchange membrane water electrolysis, where hydrogen was generated at a rate of 126 L h^-1 for 115 h at a 1.41 mV h^-1 degradation rate. Consequently, TPP is a promising protective layer that could stabilize oxygen evolution electrocatalysts.