Development of a Coil-Shape Photocatalysis-Plasma Synergistic Reactor for a Practical and Long-Term Usable Air-Cleaner

A novel air-cleaner with a coil-shape photocatalysis-plasma synergistic reactor was developed. The air-cleaner showed 95% ± 1% reduction of a TVOCs concentration in tobacco smoke at “single-pass” condition. Air-purification activity of the air-cleaner was stably-maintained after the treatment of 12,000 cigarettes of tobacco smoke.

Hierarchical structures hydrogel evaporator and superhydrophilic water collect device for efficient solar steam evaporation

Efficient light absorption and trapping are of vital importance for the solar water evaporation by hydrogel-based photothermal conversion materials.Conventional strategies are focused on the development of the composition and structure of the hydrogers internal network.In our point of view,the importance of the surface structure of hydrogel has usually been underestimated or ignored.Here inspired by the excellent absorbance and water transportation ability of biological surface structure,the hierarchical structured hydrogel evaporators(HSEs)increased the light absorption,trapping,water transportation and water-air interface,which is the beneficial photothermal conversion and water evaporation.The HSEs showed a rapid evaporation rate of 1.77 kg·m^(-2)·h^(-1)at about 92%energy efficiency under one sun(1 kW·m^(-2)).Furthermore,the superhydrophilic window device was used in this work to collect the condensed water,which avoids the light-blocking caused by the water mist formed by the small droplets and the problem of the droplets stick on the device dropping back to the bulk water.Integrated with the excellent photothermal conversion hydrogel and superhydrophilic window equipment,this work provides efficient evaporation and desalination of hydrogel-based solar evaporators in practical large-scale applications.

Sodium-doped carbon nitride nanotubes for efficient visible light-driven hydrogen production

Sodium-doped carbon nitride nanotubes （Nax-CNNTs） were prepared by a green and simple two-step method and applied in photocatalytic water splitting for the first time. Transmission electron microscopy （TEM） element mapping and X-ray photoelectron spectroscopy （XPS） measurements confirm that sodium was successfully introduced in the carbon nitride nanotubes （CNNTs）, and the intrinsic structure of graphitic carbon nitride （g-C3N4） was also maintained in the products. Moreover, the porous structure of the CNNTs leads to relatively large specific surface areas. Photocatalytic tests indicate that the porous tubular structure and Na＋ doping can synergistically enhance the hydrogen evolution rate under visible light （λ 〉 420 nm） irradiation in the presence of sacrificial agents, leading to a hydrogen evolution rate as high as 143 μmol·h-1 （20 mg catalyst）. Moreover, other alkali metal-doped CNNTs, such as Lix-CNNTs and Kx-CNNTs, were tested; both materials were found to enhance the hydrogen evolution rate, but to a lower extent compared with the Nax-CNNTs. This highlights the general applicability of the present method to prepare alkali metal-doped CNNTs; a preliminary mechanism for the photocatalytic hydrogen evolution reaction in the Nax-CNNTs is also proposed.

Hydrogel photocatalysts for efficient energy conversion and environmental treatment

Photocatalysts have attracted great research interest owing to their excellent properties and potential for simultaneously addressing challenges related to energy needs and environmental pollution.Photocatalytic particles need to be in contact with their respective media to exhibit efficient photocatalytic performances.However,it is difficult to separate nanometer-sized photocatalytic materials from reaction media later,which may lead to secondary pollution and a poor recycling performance.Hydrogel photocatalysts with a three-dimensional(3D)network structures are promising support materials for photocatalysts based on features such as high specific surface areas and adsorption capacities and good environmental compatibility.In this review,hydrogel photocatalysts are classified into two different categories depending on their elemental composition and recent progresses in the methods for preparing hydrogel photocatalysts are summarized.Moreover,current applications of hydrogel photocatalysts in energy conversion and environmental remediation are reviewed.Furthermore,a comprehensive outlook and highlight future challenges in the development of hydrogel photocatalysts are presented.

Electrochemical reduction of CO_2 and degradation of KHP on boron-doped diamond electrodes in a simultaneous and enhanced process

In this research a novel electrochemical system using dual boron-doped diamond (BDD) electrodes as the anode and cathode, for the first time, has been developed for CO_2 conversion and wastewater treatment in a synergetic and simultaneous process. On the BDD cathode CO_2 is converted into formaldehyde while in the anodic side organic wastes are decomposed on the BDD anode. Interestingly, when potassium hydrogen phthalate (KHP) was used as the organic model to be degraded in the anodic side, a higher efficiency of formaldehyde generation from CO_2 was observed on the BDD cathode. The enhanced effect of formaldehyde formation in the presence of KHP oxidation suggests that this novel electrochemical system can combine conversion of CO_2 to the form of high-value chemicals and wastewater purification in a simultaneous and harmonious process.