Improved nitrogen reduction electroactivity by unique MoS_(2)‐SnS_(2) heterogeneous nanoplates supported on poly(zwitterionic liquids)functionalized polypyrrole/graphene oxide

Unique MoS_(2)‐SnS_(2)heterogeneous nanoplates have successfully in‐situ grown on poly(3‐(1‐vinylimidazolium‐3‐yl)propane‐1‐sulfonate)functionalized polypyrrole/graphene oxide(PVIPS/PPy/GO).PVIPS can attract heptamolybdate ion(Mo7O246−)and Sn^(4+)as the precursors by the ion‐exchange,resulting in the simultaneous growth of 1T’‐MoS2 and the berndtite‐2T‐type hexagonal SnS_(2)by the interfacial induced effect of PVIPS.The obtained MoS_(2)‐SnS_(2)/PVIPS/PPy/GO can serve as electrocatalysts,exhibiting good NRR performance by the synergistic effect.The semi‐conducting SnS_(2)would limit the surface electron accessibility for suppressing HER process of 1T’‐MoS_(2),while metallic 1T’‐MoS_(2)might efficiently improve the NRR electroactivity of SnS_(2)by the creation of Mo‐Sn‐Sn trimer catalytic sites.Otherwise,the irreversible crystal phase transition has taken place during the NRR process.Partial 1T’‐MoS_(2)and SnS_(2)have electrochemically reacted with N_(2),and irreversibly converted into Mo^(2)N and SnxNz due to the formation of Mo−N and Sn−N bonding,meanwhile,partial SnS_(2) has been irreversibly evolved into SnS due to the reduction by the power source in the electrochemical system.It would put forward a new design idea for optimizing the preparation method and electrocatalytic activity of transition metal dichalcogenides.

Low-overpotential electrochemical ammonia synthesis using BiOCl-modified 2D titanium carbide MXene

Electrochemical synthesis of ammonia has the advantages of low energy consumption and promising environmental protection,as compared to the traditional Haber-Bosch process.However,the commercial utilization of this novel system is limited by the low Faradaic efficiency,poor ammonia yield and high overpotential due to the strong NN bond and the dominant competing reaction of hydrogen evolution reaction(HER).Herein,a BiOCl-modified two-dimensional(2D)titanium carbide MXenes nanocomposite(BiOCl@Ti_(3)C_(2)T_(x))is proposed as a promising electrocatalyst for ambient nitrogen(N_(2))reduction reaction with excellent catalytic performance and superior long-term stability at low overpotential.In 0.1 mol/L HCl,this catalyst attains a high Faradic efficiency of 11.98%and a NH_(3)yield of 4.06μg h^(-1)cm^(-2)at-0.10 V(vs.RHE),benefiting from its strong interaction of Bi 6p band with the N 2p orbitals,combined with its large specific surface area and the facile electron transfer.

Binary trinuclear metal-oxo sub-nanomaterials for photocatalytic hydrogen and chlorine production from seawater

Owing to the need for regenerant and self-reduction problem,the hydrogen performance of sub-nano-sized trinuclear iron-oxo complexes is still far from satisfied with affordability and practicality.Herein,two binary photocatalytic systems based on trinuclear metal-oxo complexes have been first constructed and experimentally confirmed to be competent for seawater hydrogen evolution(715.4and271.9μmol of hydrogen can be found,respectively,after 48h).Notably,chloride ions act as the hole catcher and move into the gas phase in the stable form of chlorine.Similar to heterogeneous structures,homogeneous systemsnot only enhance the hydrogen performance while ensuring the stability of metal-oxo complexes,but also shorten the consumption of photogenerated carriers by dissolved impurities in the seawater.This new attempt of building pluralistic sub-nanometric systems may offer novel design strategies with noble-metal-free catalysts and low-cost candidates for traditional semiconductor materials in enhancing photocatalytic efficiency and performing chlorine evolution from seawater splitting.