2020 Roadmap on two-dimensional nanomaterials for environmental catalysis

Environmental catalysis has drawn a great deal ofattention due to its clean ways to produce useful chemicals or carry out some chemical processes.Photocatalysis and electrocatalysis play important roles in these fields.They can decompose and remove organic pollutants from the aqueous environment,and prepare some fine chemicals.Moreover,they also can carry out some important reactions,such as 02 reduction reaction(ORR),O2 evolution reaction(OER),H2 evolution reaction(HER),CO2 reduction reaction(C02 RR),and N2 fixation(NRR).For catalytic reactions,it is the key to develop high-performance catalysts to meet the demand fortargeted reactions.In recentyears,two-dimensional(2 D) materials have attracted great interest in environmental catalysis due to their unique layered structures,which offer us to make use of their electronic and structural characteristics.Great progress has been made so far,including graphene,black phosphorus,oxides,layered double hydroxides(LDHs),chalcogenides,bismuth-based layered compounds,MXenes,metal organic frameworks(MOFs),covalent organic frameworks(COFs),and others.This content drives us to invite many famous groups in these fields to write the roadmap on two-dimensional nanomaterials for environmental catalysis.We hope that this roadmap can give the useful guidance to researchers in future researches,and provide the research directions.

Ordering effects of cholesterol on sphingomyelin monolayers investigated by high-resolution broadband sum-frequency generation vibrational spectroscopy

This report investigated the ordering of the alky chain of sphingomyelin （SMs） monolayers induced by cholesterol at the air/water interface using high-resolution broadband sum frequency generation vibrational spectroscopy （HR-BB-SFG-VS）. The SFG spectra of the three nature sphingomyelin/cholesterol mixture monolayers with two concentrations of the cholesterol at the air/water interface are performed under different polarization combination. A new resolved CH2 symmetric stretching （d＋, ~2834 cm-1） and the CH3 symmetric stretching （r＋, ~2874 cm-1） mode are applied to characterize the conformational order in the sphingomyelin/cholesterol mixture monolayers. It was found that the cholesterol make the sphingosine backbones more conformational order. During this process, the conformational order of the N-linked acyl chain remains unaltered. Moreover, the sphingosine backbones of SMs have much larger contributions to gauche defects of SMs than one in the N-linked acyl chain. These results presented here not only shed lights on understanding of the interactions of sphingomyelin molecules with cholesterol molecules at interface but also demonstrates the ability of HR-BB-SFG to probe such complicated molecular systems.