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A CdS (MOF)/PI heterojunction is prepared by in-situ growing MOF-derived CdS (MOF) on the surface of PI. The large amount of surface vacancies CdS (MOF) provide abundant active sites, greatly improves the electron-hole separation efficiency.

A series of novel Ba1-xAl2Si3O4N4: xYb2+ yellow-emissive long-afterglow phosphors was successfully synthesized via a high-temperature solid-state reaction with two sintering steps. The phosphors exhibited broad band emission (full width at half maximum, FWHM = 107 nm) with a peak at 518 nm. With an increase in the Yb2+ doping content in Ba1-xAl2Si3O4N4: xYb2+ phosphors, the luminescence intensity reached a maximum at x = 0.15. The long-afterglow phosphor can be activated effectively by 254 nm UV light, and the afterglow can persist for more than 7 h. From the thermoluminescence (TL) spectrum, there are three types of electron traps, with average evaluation depths of 0.485, 0.592, and 0.681 eV. The afterglow is caused by the capture and re-release of free electrons by the three trap energy levels. Finally, the thermal and chemical stability of the phosphor was tested, its luminescence intensity was 78.7% at 150 °C and 99.5% after 5 h soak in water compared to that at room temperature and original, respectively.

In this article, direct Z-scheme CuO/PI heterojunction photocatalyst is constructed by stripping CuO nanoparticles on the surface of polyimide (PI) through solvothermal method. TEM images display the CuO nanoparticles with {002} active exposure facet highly dispersed on the surface of PI. UV–vis, PL and TRPL spectrums confirm that these photocatalysts possess extend absorption towards visible light region. In-situ XPS technique and photodeposition characterization evidence the direct Z-scheme mechanism. The highest activity of H2 production rate achieved with EY-sensitized 20%CuO/PI photocatalyst reaches to 418.4 μmol g−1 under visible light irradiation, which is 32 times higher than that of pristine PI. The enhanced photocatalytic performance can be attributed to the direct Z-scheme charge transfer in the intimate interfacial between CuO and PI. Yet, no apparent photocatalytic activity decline is detected after four runs. Our work highlights the role of conjugated polymer in constructing efficient low-cost CuO/polymer heterojunction photocatalyst.

Magnetotactic bacteria (MTB) are a group of Gram-negative prokaryotes that respond to the geomagnetic field. This unique property is attributed to the intracellular magnetosomes, which contains membrane-bound nanocrystals of magnetic iron minerals. This review summarizes the most recent advances in MTB, magnetosomes, and their potential applications especially the environmental pollutant control or remediation. The morphologic and phylogenetic diversity of MTB were first introduced, followed by a critical review of isolation and cultivation methods. Researchers have devoted to optimize the factors, such as oxygen, carbon source, nitrogen source, nutrient broth, iron source, and mineral elements for the growth of MTB. Besides the applications of MTB in modern biological and medical fields, little attention was made on the environmental applications of MTB for wastewater treatment, which has been summarized in this review. For example, applications of MTB as adsorbents have resulted in a novel magnetic separation technology for removal of heavy metals or organic pollutants in wastewater. In addition, we summarized the current advance on pathogen removal and detection of endocrine disruptor which can inspire new insights toward sustainable engineering and practices. Finally, the new perspectives and possible directions for future studies are recommended, such as isolation of MTB, genetic modification of MTB for mass production and new environmental applications. The ultimate objective of this review is to promote the applications of MTB and magnetosomes in the environmental fields.

A series of novel blue-emitting Ba1-xAl2Si3O4N4: xEu2+ phosphors were successfully prepared by two-steps high temperature solid state reaction. The results of XRD and SEM showed that the two-steps method obtain less impurities than the traditional one-step method. The electronic band structure of BaAl2Si3O4N4 (BASON) host was calculated as a direct band gap of 3.662eV by the DFT method. The PLE spectrum of B1-xASON: xEu2+ showed a wide band excitation in the wavelength range of 250–450 nm, which can be well matched with n-UV chips. Based on crystal structural and fluorescence lifetime analysis, three emission peaks were obtained by gaussian fitting to explain the asymmetry of Eu2+ emission in the BASON phosphor. The optimal doping concentration of Eu2+ was x = 0.04. According to calculated critical distance (3.24 A) and a little overlap between PLE and PL spectra, the concentration quenching mechanism was confirmed as both of dipole-dipole interaction and radiation reabsorption. In addition, with the incorporation of Eu2+, the diffuse reflection spectrum of B1-xASON: xEu2+ presented a wide absorption peak in the range of 200–500 nm. The PL intensity of Ba0.96-ySryAl2Si3O4N4: 0.04Eu2+ tended to rise first and then fall with the increase of Sr2+ concentration. Impressively, the relative emission intensity at 473K still maintained 95.7% compared with room temperature (293K), which indicated the excellent thermal stability of BASON phosphor. Finally, the density of state (DOS) of Ba1-ySryAl2Si3O4N4 (y = 0, 0.5, 1) were calculated and analyzed to explain the deterioration of thermal stability with the increase of Sr2+ substitution.

High efficiency hydrogen generation from water has been achieved in sulfide-polymer heterojunction. In this work, a novel direct Z-scheme CdS/polyimide heterojunction was fabricated by in situ growth of CdS nanoparticles on polyimide (PI) ultrathin nanosheets through solvothermal method. The highest activity achieved on 15%CdS/PI sample reaches to H2-production rate of 613 μmol h−1 g−1 under visible-light irradiation, which is nearly 5 and 60 times higher than that of neat CdS and 1%Pt/PI. Most importantly, the excellent photostability is also achieved over 15% CdS/PI. The enhanced photocatalytic performance and photostability can be attributed to the direct Z-scheme charge transfer in the intimate interfacial between CdS and PI, which accelerates the charges separation and effective suppress of the photocorrosion in CdS/PI heterojunction. The direct Z-scheme charge transfer mechanism is evidenced by in-situ XPS analysis and time-resolved fluorescence (TRPL) decay. This work highlights the role of polymer in constructing efficient sulfide/polymer heterojunction photocatalyst.