Xun He

Work in mesoporous silica-based materials began in the early 1990s with work by Mobil. These materials had pore sizes from 20-500 A and surface areas of up to 1500 m(2) g(-1) and were synthesized by a novel liquid crystal templating approach. Researchers subsequently extended this strategy to the synthesis of mesoporous transition metal oxides, a class of materials useful in catalysis, electronic, and magnetic applications because of variable oxidation states, and populated d-bands-features not found in silicates. These materials are already showing promise in electronic and optical applications hinging on the semiconducting properties of transition metal oxides and their potential to act as electron acceptors, an important feature in the design of cathodic materials. This is the first general review of non-silicate mesoporous materials and will focus on recent advances in this area, emphasizing materials possessing unique electronic, magnetic, or optical properties. Also covered are advances in the synthesis and applications of mesostructured sulfides as well as a new class of template-synthesized platinum-based materials that show promise in heterogeneous catalysis.

NiFeS nanosheet array on Ni foam (NiFeS/NF) behaves as a superb bifunctional electrocatalyst for overall seawater splitting, attaining a commercially demanded current density of 500 mA cm −2 at a low cell voltage of 1.85 V with robust stability.

Abstract Seawater electrolysis is an attractive way of making H 2 in coastal areas, and NiFe‐based materials are among the top options for alkaline seawater oxidation (ASO). However, ample Cl − in seawater can severely corrode catalytic sites and lead to limited lifespans. Herein, we report that in situ carbon oxyanion self‐transformation (COST) from oxalate to carbonate on a monolithic NiFe oxalate micropillar electrode allows safeguard of high‐valence metal reaction sites in ASO. In situ/ex situ studies show that spontaneous, timely, and appropriate COST safeguards active sites against Cl − attack during ASO even at an ampere‐level current density ( j ). Our NiFe catalyst shows efficient and stable ASO performance, which requires an overpotential as low as 349 mV to attain a j of 1 A cm −2 . Moreover, the NiFe catalyst with protective surface CO 3 2− exhibits a slight activity degradation after 600 h of electrolysis under 1 A cm −2 in alkaline seawater. This work reports effective catalyst surface design concepts at the level of oxyanion self‐transformation, acting as a momentous step toward defending active sites in seawater‐to‐H 2 conversion systems.