Limited by the relatively low specific surface area and small quantity of active sites of semiconductor photocatalysts, the photocatalytic nitrogen fixation performance remains very low, as expected. Herein, rutile titanium dioxide (TiO2) nanoparticles with large specific surface area and abundant oxygen vacancy were designed for photocatalytic nitrogen fixation. The TiO2 photocatalysts exhibit high photocatalytic performance for nitrogen fixation in the presence of methanol as the hole scavenger, with the highest ammonia generation rate of 116 μmol·g–1·h–1, exceeding 6.5 times that of P25. This study provides a simple and facile method to prepare highly reactive TiO2 photocatalysts for enhanced photocatalytic nitrogen fixation performance.

Two-dimensional (2D) semiconductors for photocatalysis are more advantageous than the other photocatalytic materials since the 2D semiconductors generally have large specific surface area and abundant active sites. Phosphorus silicon (SiP), with an indirect bandgap in bulk and a direct bandgap in the monolayer, has recently emerged as an attractive 2D material because of its anisotropic layered structure, tunable bandgap, and high charge carrier mobility. However, the utilization of SiP as a photocatalyst for photocatalysis has been scarcely studied experimentally. Herein, we reported the synthesis of SiP nanosheets (SiP NSs) prepared from bulk SiP by an ultrasound-assisted liquid-phase exfoliation approach which can act as a metal-free, efficient, and visible-light-responsive photocatalyst for photocatalytic H2 production and nitrogen fixation. In a half-reaction system, the maximal H2 and NH3 generation rate under visible light irradiation achieves 528 and 35 μmol·h–1·g–1, respectively. Additionally, the apparent quantum yield for H2 production at 420 nm reaches 3.56%. Furthermore, a Z-scheme photocatalytic overall water-splitting system was successfully constructed by using Pt-loaded SiP NSs as the H2-evolving photocatalyst, Co3O4/BiVO4 as the O2-evolving photocatalyst, and Co­(bpy)3 3+/2+ as an electron mediator. Notably, the highest H2 and O2 generation rate with respect to Pt/SiP NSs achieves 71 and 31 μmol·h–1·g–1, respectively. This study explores the potential application of 2D SiP as a metal-free visible-light-responsive photocatalyst for photocatalysis.

Z-scheme system was successfully constructed for visible light driven photocatalytic H2 production from lignocelluloses, the highest H2 evolution rate of this Z-scheme system achieves 5.3 and 1.6 μmol•h-1 in α-celluloses...

Background:Asthma is a common chronic respiratory disease and is related to air pollution exposure. However, only a few studies have concentrated on the association between air pollution and adult asthma. Moreover, the results of these studies are controversial. Therefore, the present study aimed to analyze the influence of various pollutants on hospitalization due to asthma in adults.Methods:A total of 1019 unrelated hospitalized adult asthma patients from Northeast China were recruited from 2014 to 2016. Daily average concentrations of air pollutants (particulate matter <2.5 μm [PM2.5], particulate matter <10 μm [PM10], sulfur dioxide [SO2], nitrogen dioxide [NO2], and carbon monoxide [CO]) were obtained from the China National Environmental Monitoring Centre website from 2014 to 2016. Cox logistic regression analysis was used to analyze the relationship between air pollutants and hospital admissions in adult asthma.Results:The maximum odds ratio (OR) value for most air pollutants occurred on lag day 1. Lag day 1 was chosen as the exposure period, and 8 days before onset was chosen as the control period. Three pollutants (PM2.5, CO, and SO2) were entered into the regression equation, and the corresponding OR (95% confidence interval) was 0.995 (0.991–0.999), 3.107 (1.607–6.010), and 0.979 (0.968–0.990), respectively.Conclusions:A positive association between hospital admissions and the daily average concentration of CO was observed. CO is likely to be a risk factor for hospital admissions in adults with asthma.

The photothermal effects have shown the possibilities for applications in optical manipulation. In this paper, an approach is demonstrated to generate and manipulate a bubble using the photothermal effects. First, a high-power laser is used to irradiate the light absorbing particles for creating a microbubble. The bubble grows up to a diameter of a few hundred micrometers in several seconds due to the diffusion of dissolved gases. The bubble does not float up and is confined at the lower boundary of the sample cell by the thermocapillary force. The force is induced by laser heating of the particles at the bubble base. Second, the bubble can be manipulated following the laser focal spot. The bubble is dragged by the horizontal component of thermocapillary force. The bubble re-grows as it moves because it absorbs the dissolved gases in its migration path. The bubble floats up finally when it grows up to the maximum size. The perpendicular component of thermocapillary force can be estimated equal to the buoyancy of the floated bubble and is about 38 nN at the laser power of 130 mW. Furthermore, we show the generation and manipulation of the bubbles in a capillary. The reason for the decrease in movement velocity in the capillaries has been studied and discussed. The approach of bubble manipulation shows a potential application in transporting the microparticles.