Wettability control of defective TiO_(2)with alkyl acid for highly efficient photocatalytic ammonia synthesis

Ammonia is an important chemical raw material and non-carbon-based fuel.Photocatalytic ammonia production technology as a mild alternative to the traditional Harbor–Bosch route is carried out at the air,liquid,and solid three-phase interface.Promoting the activation of N_(2),depressing hydrogen evolution reaction(HER),and increasing the local N_(2) concentration around the catalyst surface are critical factors in achieving high conversion efficiency.In this paper,we proposed that defective TiO_(2)is surfacemodified by alkyl acids with different carbon chain lengths(C_(2),C_(5),C_(8),C_(11),and C_(14))to tune the catalyst surface properties.The defect sites greatly promote N_(2) adsorption and activation.The wettability of the catalyst can be regulated from hydrophilic to hydrophobic by the length of the alkyl chain.The hydrophobic surface enhances the N_(2) adsorption and increases the local N_(2) concentration due to its aerophile.Meanwhile,it depresses the proton adsorption and HER.Overall,the nitrogen reduction reaction(NRR)is greatly promoted.Among the series of samples,they present a systematic change and have a maximal NRR performance for n-octanoic acid-defective TiO_(2)(C8-Vo-TiO_(2);Vo=oxygen vacancy).The rate of ammonia production can be as high as 392μmol·g^(−1)·h^(−1).This work provides a new strategy for efficient ammonia synthesis at the three-phase interface using photocatalyst technology.

Hydrocarbon origin and reservoir forming model research of Longwangmiao Formation,Moxi-Gaoshiti area,Sichuan Basin

This paper focuses on the Longwangmiao gas reservoir in Moxi-Gaoshiti area,Sichuan Basin.Starting from the tectonic evolution perspective,though comparing biological marker compound and analyzing fluid inclusions,the oil&gas origin and accumulation evolution of Longwangmiao Formation are systematic studied with reference to the burial-thermal evolution of single well geological history in the study area.It is suggested that the oil&gas reservoir is generally characterized by early accumulation,multi-stage filling,late cracking and later adjustment.The oil and gas were mainly sourced from lower Cambrian Qiongzhusi Formation,partly from the Permian source rock.During the geological period,3 major oil&gas fillings occurred in the Longwangmiao Formation,namely Caledonian-Hercynian filling that was small in scale and produced the first phase of paleo-oil reservoir that soon destroyed by Caledonian movement uplift,large-scale Permian filling that gave rise to the second-phase of paleo-oil reservoir and the Triassic-Jurassic filling that enriched the second phase of paleo-oil reservoir.Finally,the paleo-oil reservoir experienced an in-situ cracking during the cretaceous period that gave rise to a natural gas reservoir and left behind carbonaceous bitumen and oily bitumen in the holes of the Longwangmiao Formation.

Establishing carrier transport channels based on Ti-S bonds and enhancing the photocatalytic performance of MXene quantum dots-ZnIn2S4 for ammonia

In the process of photocatalytic synthesis of ammonia,the kinetics of carrier separation and transport,adsorption of nitrogen,and activation of the N N triple bond are key factors that directly affect the efficiency of converting nitro-gen to ammonia.Here,we report a new strategy for anchoring MXene quan-tum dots(MXene QDs)onto the surface of ZnIn2S4 by forming Ti-S bonds,which provide a channel for the rapid separation and transport of charge car-riers and effectively extend the lifespan of photogenerated carriers.The unique charge distribution caused by the sulfurization of the MXene QDs further enhances the performance of the photocatalysts for the adsorption and activa-tion of nitrogen.The photocatalytic ammonia synthesis efficiency of MXene QDs-ZnIn2S4 can reach up to 360.5μmol g�1 h�1.Density functional theory calculations,various in situ techniques,and ultrafast spectroscopy are used to characterize the successful construction of Ti-S bonds and the dynamic nature of excited state charge carriers in MXene QDs-ZnIn2S4,as well as their impact on nitrogen adsorption activation and photocatalytic ammonia synthesis efficiency.This study provides a new example of how to improve nitrogen adsorp-tion and activation in photocatalytic material systems and enhance charge carrier dynamics to achieve efficient photocatalytic nitrogen conversion.