Bandgap engineering control bifunctional MnxCd1-xS photocatalysts selectively reforming xylose to C3 organic acids and efficient hydrogen production.

The simultaneous reforming of biomass into high value-added chemicals and H2 production by water splitting in a green and environmentally clean way is a very challenging task. Herein, we demonstrate the design of bifunctional MnxCd1-xS photocatalyst with a controllable band gap by bandgap engineering. Bandgap engineering effectively regulates the oxidation and reduction capacity of materials. The design of photocatalysts with suitable conduction bands and valence bands makes the targeted conversion of xylose possible. Innovative conversion of xylose to glyceric acid, lactic acid, and propanoic acid. The optimized Mn0.7Cd0.3S catalyst showed excellent performance in the production of H2 (14.06 mmol·gcat-1·h-1, 29.9 times more than CdS and 351.5 times more than MnS), xylose conversion (90%), and C3 organic acid yield (59.2%) without cocatalyst and any scavengers under visible light irradiation. This work shows that a rational photocatalyst design can achieve efficient simultaneous production of high value-added chemicals and clean energy.

A biodegradable nano-photosensitizer with photoactivatable singlet oxygen generation for synergistic phototherapy.

Photodynamic therapy (PDT) is a promising method for cancer therapy and also may initiate unexpected damages to normal cells and tissues. Herein, we develop a near-infrared (NIR) light-activatable nanophotosensitizer, which shows negligible phototoxicity before photoactivation to improve the specificity of PDT. The nanophotosensitizer is prepared by indocyanine green carboxylic (ICG), Chlorin e6 (Ce6), and biodegradable poly (lactic acid) (PLA) and poly (lactic-co-glycolic acid) (PLGA), and all these materials have been approved by the Food and Drug Administration. Initially the phototoxicity of Ce6 is effectively inhibited by ICG through fluorescence resonance energy transfer (FRET). Upon 808 nm laser activation, ICG generate hyperthermia for photothermal therapy (PTT) and simultaneously is degraded due to the inherently poor photostability. The FRET is disrupted and followed by the recovery of phototoxicity of Ce6 for PDT. We investigated the photoactivation and the resulting phototherapy by cellular assays and mouse models, which indicate a superior synergistic treatment effect and selective PDT activated by near-infrared 808 nm light. This study presents a promising strategy for activatable and synergistic phototherapy with minimal damage to normal tissues.

Erbium Single Atom Composite Photocatalysts for Reduction of CO2 under Visible Light: CO2 Molecular Activation and 4f Levels as an Electron Transport Bridge.

It is still challenging to design a stable and efficient catalyst for visible-light CO2 reduction. Here, Er3+ single atom composite photocatalysts are successfully constructed based on both the special role of Er3+ and the special advantages of Zn2 GeO4 /g-C3 N4 heterojunction in the photocatalysis reduction of CO2 . Especially, Zn2 GeO4 :Er3+ /g-C3 N4 obtained by in situ synthesis is not only more conducive to the tight junction of Zn2 GeO4 and g-C3 N4 , but also more favorable for g-C3 N4 to anchor rare-earth atoms. Under visible-light irradiation, Zn2 GeO4 :Er3+ /g-C3 N4 shows more than five times enhancement in the catalytic efficiency compared to that of pure g-C3 N4 without any sacrificial agent in the photocatalytic reaction system. A series of theoretical and experimental results show that the charge density around Er, Ge, Zn, and O increases compared with Zn2 GeO4 :Er3+ , while the charge density around C decreases compared with g-C3 N4 . These results show that an efficient way of electron transfer is provided to promote charge separation, and the dual functions of CO2 molecular activation of Er3+ single atom and 4f levels as electron transport bridge are fully exploited. The pattern of combining single-atom catalysis and heterojunction opens up new methods for enhancing photocatalytic activity.

Enhanced luminescence through interface energy transfer in hierarchical heterogeneous nanocomposites and application in white LEDs.

Highly efficient light-emitting materials are essential for achieving high-performance devices. Here, a novel composite system, as well as enhanced luminescence processes, was designed, where NaLn(MoO4)2 ultra-small nucleus can be effectively isolated by In(OH)3 to form NaLn(MoO4)2@In(OH)3 composite nanoclusters due to the different nucleation rate between NaLn(MoO4)2 and In(OH)3, and then these small composite clusters gradually self-assemble into hierarchical structures. As we expected, the enhanced luminescence was achieved from hierarchical NaLn(MoO4)2 nanostructures with adjusting the distance among NaLn(MoO4)2 ultra-small nucleus by inserting In(OH)3. A series of spectroscopy results show that the In(OH)3 not only acts as an energy transfer bridge from CTB Eu3+ → O2- (or MoO42- absorption) to Eu3+, but also can effectively alleviate the concentration quenching of Ln3+ and change the J-O parameters. The Raman peak at 134 cm-1 is helpful to populate the 5D0 level of Eu3+ or the excited states of Er3+, resulting in stronger up/down-conversion emissions. The use of NaLn(MoO4)2@In(OH)3 in white light-emitting diodes (LEDs) has been demonstrated. The combination of red emission from NaLn(MoO4)2@In(OH)3 with blue, green, and yellow emission from halide perovskites could achieve white light with excellent vision performance (an LER of 376 lm/W) and superior color quality (CRI > 92). The findings of this experiment provide a new idea for the design of composite interface materials.

Multifunctional NaLnF4@MOF-Ln Nanocomposites with Dual-Mode Luminescence for Drug Delivery and Cell Imaging.

Multifunctional nanomaterials for bioprobe and drug carrier have drawn great attention for their applications in the early monitoring the progression and treatment of cancers. In this work, we have developed new multifunctional water-soluble NaLnF4@MOF-Ln nanocomposites with dual-mode luminescence, which is based on stokes luminescent mesoporous lanthanide metal-organic frameworks (MOFs-Y:Eu3+) and anti-stokes luminescent NaYF4:Tm3+/Yb3+ nanoparticles. The fluorescence mechanism and dynamics are investigated and the applications of these nanocomposites as bioprobes and drug carriers in the cancer imaging and treatment are explored. Our results demonstrate that these nanocomposites with the excellent two-color emission show great potential in drug delivery, cancer cell imaging, and treatment, which are attributed to the unique spatial structure and good biocompatibility characteristics of NaLnF4@MOF-Ln nanocomposites.