Modulation effects of S vacancy and Mo edge on the adsorption and dissociation behaviors of toxic gas (H2S, SO2) molecules on the MoS2 monolayer

Review of Theoretical and Computational Studies of Bulk and Single Atom Catalysts for H2 S Catalytic Conversion

Catalytic conversion of hydrogen sulfide (H2 S) plays a vital role in environmental protection and safety production. In this review, recent theoretical advances for catalytic conversion of H2 S are systemically summarized. Firstly, different mechanisms of catalytic conversion of H2 S are elucidated. Secondly, theoretical studies of catalytic conversion of H2 S on surfaces of metals, metal compounds, and single-atom catalysts (SACs) are systematically reviewed. In the meantime, various strategies which have been adopted to improve the catalytic performance of catalysts in the catalytic conversion of H2 S are also reviewed, mainly including facet morphology control, doped heteroatoms, metal deposition, and defective engineering. Finally, new directions of catalytic conversion of H2 S are proposed and potential strategies to further promote conversion of H2 S are also suggested: including SACs, double atom catalysts (DACs), single cluster catalysts (SCCs), frustrated Lewis pairs (FLPs), etc. The present comprehensive review can provide an insight for the future development of new catalysts for the catalytic conversion of H2 S.

Toxic gas sensing performance of arsenene functionalized by single atoms (Ag, Au): a DFT study

The detection and removal of toxic gases from the air are imminent tasks owing to their hazards to the environment and human health. Based on DFT calculations with VdW correction, adsorption configurations, adsorption energies, and electronic properties were compared for the adsorption of toxic gas molecules (CO, NO, NO2, SO2, NH3 and H2S) on pure arsenene (p-arsenene) and Ag/Au-doped arsenene (Ag/Au-arsenene). Our calculations show that all molecules considered to chemisorb on Ag/Au-arsenene and the substitution of noble metal, particularly Ag, could remarkably enhance the interactions and charge transfer between the gas molecules and Ag/Au-arsenene. Thus, Ag/Au-arsenene is expected to show higher sensitivity in detecting CO, NO, NO2, SO2, NH3 and H2S molecules than p-arsenene. Furthermore, the changes in the vibrational frequencies of gas molecules and the work functions of Ag/Au-arsenene substrates upon adsorption are shown to be closely related to the adsorption energies and charge transfer between the molecules and Ag/Au-arsenene, which is dependent on the molecules. Therefore, Ag/Au-arsenene-based gas sensors are expected to show good selectivity of molecules. The analysis of theoretical recovery time suggested that Ag-arsenene shows high reusability while detecting H2S, CO, and NO, whereas Au-arsenene has high selectivity to sensing NO at room temperature. With the increase in work temperature and decrease in recovery times, Ag/Au-arsenene could be used to detect NH3 and NO2 from factory emission and automobile exhaust with quite good reusability. The above results indicated that Ag/Au-arsenene shows good performance in toxic gas sensing with high sensitivity, selectivity, and reusability at different temperatures.

An H2 S-BMP6 Dual-Loading System with Regulating Yap/Taz and Jun Pathway for Synergistic Critical Limb Ischemia Salvaging Therapy

Critical limb ischemia, the final course of peripheral artery disease, is characterized by an insufficient supply of blood flow and excessive oxidative stress. H2 S molecular therapy possesses huge potential for accelerating revascularization and scavenging intracellular reactive oxygen species (ROS). Moreover, it is found that BMP6 is the most significantly up-expressed secreted protein-related gene in HUVECs treated with GYY4137, a H2 S donor, based on the transcriptome analysis. Herein, a UIO-66-NH2 @GYY4137@BMP6 co-delivery nanoplatform to strengthen the therapeutic effects of limb ischemia is developed. The established UIO-66-NH2 @GYY4137@BMP6 nanoplatform exerts its proangiogenic and anti-oxidation functions by regulating key pathways. The underlying molecular mechanisms of UIO-66-NH2 @GYY4137@BMP6 dual-loading system lie in the upregulation of phosphorylated YAP/TAZ and Jun to promote HUVECs proliferation and downregulation of phosphorylated p53/p21 to scavenge excessive ROS. Meanwhile, laser-doppler perfusion imaging (LDPI), injury severity evaluation, and histological analysis confirm the excellent therapeutic effects of UIO-66-NH2 @GYY4137@BMP6 in vivo. This work may shed light on the treatment of critical limb ischemia by regulating YAP, Jun, and p53 signaling pathways based on gas-protein synergistic therapy.