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In recent years, reactive species-based cancer therapies have attracted tremendous attention due to their simplicity, controllability, and effectiveness. Herein, we overviewed the state-of-art advance for photo-controlled generation of highly reactive radical species with nanomaterials for cancer therapy. First, we summarized the most widely explored reactive species, such as singlet oxygen, superoxide radical anion (O2●-), nitric oxide (●NO), carbon monoxide, alkyl radicals, and their corresponding secondary reactive species generated by interaction with other biological molecules. Then, we discussed the generating mechanisms of these highly reactive species stimulated by light irradiation, followed by their anticancer effect, and the synergetic principles with other therapeutic modalities. This review might unveil the advantages of reactive species-based therapeutic methodology and encourage the pre-clinical exploration of reactive species-mediated cancer treatments., Graphical abstract Reactive species-based cancer therapy modalities triggered-by light irradiation have been paid tremendous attention due to their distinct advantages. Here, we overviewed the latest advances involving the material design and biomedical application mechanism of reactive oxygen, reactive nitrogen and reactive carbon species.Image 1, Highlights • The most widely explored reactive species, such as 1O2, O2●-, ●NO, CO, alkyl radicals are specifically summarized. • The generating mechanisms of these reactive species triggered-by light irradiation are overviewed. • This review will unveil the innate advantages of reactive species-based therapeutic methodology.

Both phototherapy via photocatalysts and physical puncture by artificial nanostructures are promising substitutes for antibiotics when treating drug-resistant bacterial infectious diseases. However, the photodynamic therapeutic efficacy of photocatalysts is seriously restricted by the rapid recombination of photogenerated electron–hole pairs. Meanwhile, the nanostructures of physical puncture are limited to two-dimensional (2D) platforms, and they cannot be fully used yet. Thus, this research developed a synergistic system of Ag3PO4 nanoparticles (NPs), decorated with black urchin-like defective TiO2 (BU–TiO2-X/Ag3PO4). These NPs had a decreased bandgap compared to BU-TiO2-X, and BU-TiO2-X/Ag3PO4 (3:1) exhibited the lowest bandgap and the highest separation efficiency for photogenerated electron–hole pairs. After combination with BU-TiO2-X, the photostability of Ag3PO4 improved because the oxygen vacancy of BU-TiO2-X retards the reduction of Ag+ in Ag3PO4 into Ag0, thus reducing its toxicity. In addition, the nanospikes on the surface of BU-TiO2-X can, from all directions, physically puncture bacterial cells, thus assisting the hybrid's photodynamic therapeutic effects, alongside the small amount of Ag+ released from Ag3PO4. This achieves synergy, endowing the hybrid with high antibacterial efficacy of 99.76 ± 0.15% and 99.85 ± 0.09% against Escherichia coli and Staphylococcus aureus, respectively, after light irradiation for 20 min followed by darkness for 12 h. It is anticipated that these findings may bring new insight for developing synergistic treatment strategies against bacterial infectious diseases or pathogenic bacterial polluted environments., Graphical abstract Image 1, Highlights • BU-TiO2-X/Ag3PO4 (3:1) hybrid improved the photostability of Ag3PO4. • BU-TiO2-X/Ag3PO4 (3:1) hybrid exhibited outstanding photodynamic therapeutic effects. • The nanospikes from all directions on the BU-TiO2-X physically punctured bacterial cells. • The physical puncture combined with the Ag+ released by Ag3PO4 had long-term bacteriostatic efficacy.

Dynamic therapy, such as photodynamic therapy (PDT) or chemodynamic therapy (CDT), is one of the most promising therapeutic strategies for tumors. Integrating the advantages of near-infrared-induced PDT and CDT can potentially improve the therapeutic performance. A single primitive nanostructure, CuWO4 nanodots, was developed. It could generate reactive oxygen species under 808 nm light irradiation and release copper ions into the acid tumor microenvironment, thereby boosting Fenton-like reactions. The PDT and CDT would occur when the nanodots were introduced into the tumor tissue and irradiated under 808 nm light. The results of combined PDT and CDT antitumor studies showed the effective inhibition of tumor tissue growth, thereby suggesting that the nanodots are candidate agents for synergistic antitumor applications.

ZnO:Graphene Oxide composite nanopowders have been successfully prepared by sol-gel method. The study of composite preparation is discussed in this paper. Graphene oxide was added in two ways in order to study the mixed behaviour especially in photocatalytic properties. The degradation of methylene blue (MB) concentration in water was used to evaluate the photocatalytic property under low UV-light irradiation (14 μW/cm2). The results showed that all varian ZnO-GO composite samples have spherical morphology and hexagonal wurtzite crystal structure. An addition of graphene oxide (GO) in ZnO precursor solution during preparation shows a better photocatalytic property that related to reducing in particle size, thereby produce a large surface area and formed a better interfacing with GO/rGO. The existence of GO around ZnO nanoparticles gives some advantageous due to presences of hydroxyl component that directly relate to the increments in photocatalytic behavior. The photodegradation rate of MB in water using ZnO-GO composite as catalyst is significantly increase compared with pure ZnO.

Intelligent systems that offer traceable cancer therapy are highly desirable for precision medicine. Although photodynamic therapy (PDT) has been approved in the clinic for decades, determining where the tumor is, when to irradiate, and how long to expose to light still confuse the clinicians. Patients are always suffering from the phototoxicity of the photosensitizer in nonmalignant tissues. Herein, an activatable theranostic agent, ZnPc@TPCB nanoparticles (NPs), is prepared by doping a photosensitizer, ZnPc, with an aggregation-induced emission probe, TPCB. The assembled or disassembled ZnPc@TPCB NPs in various phases have behaved differently in fluorescence intensity, photoacoustic (PA) signals, and PDT efficiency. The intact nanoparticles are non-emissive in aqueous media while showing strong PA signals and low PDT efficiency, which can eliminate the phototoxicity and self-monitor their distribution and image the tumors' location. Disassembling of the NPs leads to the release of ZnPc and its red fluorescence turn-on to self-report the photosensitizer's activation. Upon light irradiation, the reactive oxygen species (ROS) generated by ZnPc can induce cell apoptosis and activate the ROS sensor, TPCB, which will yield intense orange-red fluorescence and instantly predict the therapeutic effect. Moreover, enhanced PDT efficacy is achieved via the GSH-depleting adjuvant quinone methide produced by the activated TPCB. The well-designed ZnPc@TPCB NPs have shown promising potential for finely controlled PDT with good biosafety and broad application prospects in individual therapy, which may inspire the development of precision medicine.

Light-powered micromotors have drawn enormous attention because of their potential applications in cargo delivery, environmental monitoring, and noninvasive surgery. However, the existing micromotors still suffer from some challenges, including slow speed, poor controllability, single locomotion mode, and no deformation during movement. Herein, we employ a combined electrospinning with brushing of Chinese ink to simply fabricate a light-responsive gradient-structured poly(vinyl alcohol)/carbon (PVA/carbon) composite motor. Because of the surface deposition and ultrahigh loading amount of carbon nanoparticles (ca. 43%), the motor exhibits rapid (39 mm/s), direction-controlled, and multimodal locomotion (vertical movement, horizontal motion, rotation) under light irradiation. Simultaneously, gradient alignment structure of the PVA nanofibrous matrix endows the motor with controllable and reversible deformation during locomotion. We finally demonstrate the potential applications of the motors in leakage monitoring, object salvage, smart access, and intelligent assembly. The present work will inspire the design of novel photosensitive motors for applications in various fields, such as microrobots, environmental monitoring, and biomedicine.

A novel visible-light-responsive 2D/2D g-C3N4/Bi4NbO8Cl nano-composite photocatalyst was hydrothermally synthesized using g-C3N4 and Bi4NbO8Cl. Various characterization techniques were employed to characterize the as-synthesized g-C3N4/Bi4NbO8Cl nano-composites. The photocatalytic efficiency of the nano-composite materials was assessed by the degradation of an emerging pharmaceutical pollutant, oxytetracycline (OTC), under visible LED light irradiation. It was observed that at an optimum mass ratio of 20% (g-C3N4 to Bi4NbO8Cl), the 20g-C3N4/Bi4NbO8Cl nano-composite produced the highest photocatalytic degradation efficiency toward OTC. The photocatalytic degradation of OTC (20 mgL−1) by 20g-C3N4/Bi4NbO8Cl (1 gL−1), under 60 min of visible LED light irradiation was 87%, which was about 1.2 and 1.8 times higher as compared to that of pure Bi4NbO8Cl and g-C3N4, respectively. This improved performance was associated with the formation of type-II heterojunction, which resulted in better visible-light absorption and reduced recombination of photogenerated electron-hole pairs. Moreover, it was observed that after four cycles of degradation experiments, the nano-composite was stable. The results of this work not only demonstrate the construction of 2D/2D g-C3N4/Bi4NbO8Cl nano-composite for successful low-cost and energy-efficient photocatalytic degradation of recalcitrant pollutant but also motivate the production of similar photocatalysts targeting environmental remediation.

With the rapid development of materials science, photosensitive materials have been widely used in the field of immunogenic cell death(ICD), which was on account of the reactive oxygen species(ROS) generation by photosensitizer under light irradiation inducing cellular oxidative stress during the dying of cells. Considerable researches related to photodynamic therapy(PDT) induced ICD were conducted and exhibited brilliant performance in cancer immunotherapy. Herein, a variety of different strategies for PDT induced ICD have been summarized and discussed to provide researchers more inspiration for cancer immunotherapy.

Combined antitumor therapies based on nanomedicines have shown efficacy in various tumor models in recent years, overcoming the disadvantages of inefficiency and undesired toxicity of traditional therapies. Herein, we present a copper sulfide- and doxorubicin-loaded gold nanorods@mesoporous SiO2 multifunctional nanocomposite (AuNR@mSiO2@DOX-CuxS-PEG) to integrate chemotherapy, the photothermal properties of AuNRs, and the photodynamic properties of CuxS into a single nanoplatform based on hydrophobic interaction and electrostatic attraction. Upon near-infrared light irradiation, the AuNR@mSiO2@DOX-CuxS-PEG nanocomposites exhibit a synergistic therapeutic effect and inhibit the in situ tumor growth and lung metastasis in a melanoma model. This occurs because of the high photothermal conversion efficiency, boosted intracellular reactive oxygen species production, and excellent doxorubicin (DOX) release, as well as an induced tumor-specific immune response. The inspired antitumor immunity was confirmed by elevated infiltration of activated T cells in tumor tissues and improved maturation and activation of dendritic cells in tumor-draining lymph nodes. This study highlights the superior antitumor therapeutic effect elicited by a multifunctional nanoplatform for skin with in situ melanoma and lung metastasis inhibition, indicating its satisfactory clinical application prospects.

CO2 conversion has attracted widespread attention because CO2 is a major issue in global warming. In this work, a hybrid metal–organic framework (MOF) film was successfully prepared by embedding PC61BM ([6,6]-phenyl C61 butyric acid methyl ester) into a CuTCPP (TCPP: meso-tetra(4-carboxyphenyl)porphine) film through a solid conversion process. The as-prepared PC61BM/CuTCPP film exhibits a three-dimensional architecture composed of two-dimensional MOF nanosheets, having not only sufficient paths for mass transfer but also active sites exposed directly to substrates. The charge migration and separation in the heterojunction between PC61BM and CuTCPP under light irradiation can dramatically improve the CO2 conversion performance of the hybrid film. The CO2 conversion proceeds rapidly even at room temperature and 1 atm with the PC61BM@CuTCPP film as the catalyst, representing one of the best photocatalysis efficacies so far among MOF-based catalysts, with the conversion up to 92.4% and a turn-over-frequency of 36.0 h−1. This work provides an insight into designing high-performance MOF-based catalysts for CO2 conversion.

Owing to their unique physicochemical, optical and electrical properties, two-dimensional (2D) MoS2 cocatalysts have been widely applied in designing and developing highly efficient composite photocatalysts for hydrogen generation under suitable light irradiation. In this review, we first elaborated on the fundamental aspects of 2D MoS2 cocatalysts to include the structural design principles, synthesis strategies, strengths and challenges. Subsequently, we thoroughly highlighted and discussed the modification strategies of 2D MoS2 H2-evolution cocatalysts, including doping heteroatoms (e.g. metals, non-metals, and co-doping), designing interfacial coupling morphologies, controlling the physical properties (e.g. thickness, size, structural defects or pores), exposing the reactive facets or edge sites, constructing cocatalyst heterojunctions, engineering the interfacial bonds and confinement effects. In the future, the forefront challenges in understanding and in precise controlling of the active sites at molecular level or atomic level should be carefully studied, while various potential mechanisms of photogenerated-electrons interactions should be proposed. The applications of MoS2 cocatalyst in the overall water splitting are also expected. This review may offer new inspiration for designing and constructing novel and efficient MoS2-based composite photocatalysts for highly efficient photocatalytic hydrogen evolution.

Tumor accumulation and intratumoral singlet oxygen (1O2) generation efficiency of photosensitizers (PSs) are two essential factors that determine their photodynamic therapy (PDT) efficacies. How to maximize the PS performance at the tumor site is of great research interest. Herein, we report a metal-organic framework (ZIF-8, ZIF = zeolitic imidazolate framework) assisted in vivo self-assembly nanoplatform, ZIF-8-PMMA-S-S-mPEG, as an effective tool for organic PS payloads to achieve efficient PDT. Using an organic PS with aggregation-induced emission as an example, under intratumoral bioreduction, PS-loaded ZIF-8-PMMA-S-S-mPEG (PS@ZIF-8-PMMA-S-S-mPEG) was self-assembled into large ordered hydrophobic clusters, which greatly enhance tumor retention and accumulation of the PS. Moreover, hydrophobic ZIF-8 assemblies greatly isolate the loaded PSs from water and improve O2 transport for the PSs to effectively produce 1O2 inside tumors under light irradiation. The organic PS is therefore endowed with optimal tumor accumulation and intratumoral 1O2 production, demonstrating the effectiveness of the developed self-assembly strategy in PDT application.

On-chip gel actuators are potential candidates for single cell manipulation because they can realize low-invasive manipulation of various cells. We propose an on-chip gel actuator driven by light irradiation. By patterning the gel actuator with light absorber, we can control the temperature of the actuator and drive it. The proposed drive method can realize highly localized temperature control of the gel actuator and can be applied to mass integration of on-chip gel actuators. In this study, we evaluate the heat conduction of the actuator during driving and its response characteristics as a function of various design parameters. We theoretically and experimentally evaluate the response characteristics and confirm that the response characteristics can be changed by altering the size of the light absorber. Furthermore, we show some examples of cell manipulation including trapping, transport, and sorting with various sizes of light absorber. Finally, we show proof of concept for the application of the proposed drive method for massive integration of on-chip gel actuators.

We report an experimental study of the effect of visible and UV light irradiation on the wettability of films made by the assembly of SiO2 and α − Fe2O3 particles in the nanometer range. To optimiz...

Room-temperature creep tests of ZnS single crystals were conducted along the [001] direction under controlled light conditions in order to investigate the effect of light irradiation on the dislocation motion in ZnS. ZnS crystals stably deform by creep even at room temperature if the tests are conducted in complete darkness. It was found that the strain rate during a creep test can be immediately reduced by irradiating the sample with light having wavelengths of 365 nm or 436 nm even for the case when a sufficient density of mobile dislocations has been introduced due to preceding creep deformation. Surprisingly, the drop in strain rate by the light irradiation was several orders of magnitude. This drop in strain rate is believed to be due to a drastic decrease in the density of mobile dislocations, as well as the mobility of such dislocations, which are derived from the interaction with light-induced electrons and holes. It's also important to note that a significant incubation time appears when creep deformation resumes in the dark (light off) followed by loading under light irradiation during which the creep deformation is very small. This indicates that the light-induced free electrons and holes have long lifetimes in ZnS and, therefore, the existing dislocations continue interacting with electronic defects for several minutes after the light has been turned off.

In this work, TiO2/MXene composites were successfully synthesized through an in-situ solvothermal method, where the morphology of TiO2 nanoparticles (NPs) was modified by different concentrations of agents. Ti3C2Tx with electronic storage characteristics was employed as a co-catalyst to enhance the photocatalytic degradation activity by capturing photogenerated electrons. The experimental results reveal that, with the help of C3H8O agents, TiO2 NPs are uniformly distributed on the surface of Ti3C2Tx. The TiO2/Ti3C2Tx-C3H8O composite showed the highest photocatalytic activity of 90.5% after 75 min under mercury light irradiation, which is 57.9% higher than that of the pure TiO2 photocatalyst. The photocatalytic activity is promoted due to the high photoelectron transmission performance of the TiO2/Ti3C2Tx composites.

Insufficient intratumoral penetration greatly hurdles the anticancer performance of nanomedicine. To realize highly efficient tumor penetration in a precisely and spatiotemporally controlled manner, far-red light-responsive nanoclusters (NCs) capable of size shrinkage and charge conversion were developed and co-administered with iRGD to synergistically improve the intratumoral penetration and the anticancer efficacy. The NCs were constructed using the singlet oxygen-sensitive (SOS) polyethylene glycolpolyurethane-polyethylene glycol (PEG-(1O2)PU-PEG) triblock copolymer to encapsulate the doxorubicin (DOX)-loaded, chlorin e6 (Ce6)-conjugated polyamindoamine (PAMAM) dendrimer (DCD) via the double-emulsion method. Co-administration of iRGD notably increased the permeability of NCs within tumor vasculature and tumor tissues. In addition, upon far-red light irradiation (660 nm) of tumors at low optical density (10 mW/cm2), the generated 1O2 could disintegrate the NCs and release the DCD with positive surface charge and ultra-small size (∼5 nm), which synergized with iRGD to enable deep intratumoral penetration. Consequently, the local 1O2 at lethal concentrations along with the released DOX efficiently and cooperatively eradicated tumor cells. This study provides a convenient approach to spatiotemporally promote the intratumoral penetration of nanomedicine and mediate programmed anticancer therapy.

Adaptable behavior such as triggered disintegration affords a broad scope and utility for (bio)materials in diverse applications in materials science and engineering. The impact of such materials continues to grow due to the increased importance of environmental considerations as well as the increased use of implants in medical practices. However, examples of such materials are still few. In this work, we engineer triggered liquefaction of hydrogel biomaterials in response to internal, localized heating, mediated by near-infrared light as external stimulus. This adaptable behavior is engineered into the readily available physical hydrogels based on poly(vinyl alcohol), using gold nanoparticles or an organic photothermal dye as heat generators. Upon laser light irradiation, engineered biomaterials underwent liquefaction within seconds. Pulsed laser light irradiation afforded controlled, on-demand release of the incorporated cargo, successful for small molecules as well as proteins (enzymes) in their biofunctional form.

Although occupying pillar position in clinical cancer treatments, surgery itself and surgical trauma would elicit series of local/systemic inflammation-related responses that resulted in high rate of tumor recurrence. Herein, chitosan with conjugated gallic acid (CSG) molecules were coordinated with Fe3+ to form CSG/Fe3+ hydrogel for filling the tumor-resected cavity with considerable wet-adhesion ability and anti-inflammatory performance. With the assistance of doxorubicin hydrochloride (DOX∙HCl), CSG/Fe3+/DOX hydrogel exhibited synergistic photothermal-chemo tumor-inhibited performance under near-infrared (NIR) light irradiation for eradicating residual and/or surgical trauma-recruited cancer cells. Thus, our study attempts to show a paradigm that realizes quick surgical trauma healing, inflammation inhibition and prevention of postsurgical tumor recurrence.

Among the numerous materials used for dye removal, magnetite is particularly interesting due to its ability to act as an adsorbent and a Fenton catalyst, being easily separable by application of a magnetic field and reusable. Herein, we describe a co-precipitation–based synthesis of magnetite nanoparticles (particle size = 11 nm, surface area = 147.12 m2 g–1) from iron sand and investigate their effectiveness for methylene blue (MB) degradation. The above nanoparticles could promote the decomposition of MB both in the dark (via adsorption) and under UV light irradiation (via Fenton-type degradation), exhibiting the additional advantage of recyclability. Thus, MB degradation efficiencies are 76.32, 76.08, and 68.52% for first, second, and third cycles, respectively, indicating that the prepared magnetic material is a promising recyclable catalyst for the decontamination of dye-containing wastewater. The photo Fenton reactions take to account for reproducibility of MB degradation.

International audience; In this work, the design of an original series of coumarin derivatives (CoumC1-CoumC13) is presented. Chemical structures of these coumarins were selected by molecular modelling to ensure both excellent light absorption properties and high potential photoreactivity (high excited state energy). As a striking result of this in-silico design, 8 of the 13 proposed coumarins were never presented and were specifically proposed for this work, evidencing the interest of the structures. New multi-component photoinitiating systems (PISs) based on these coumarins are proposed for the free radical polymerization (FRP) of (meth)acrylates and examined upon visible light irradiation using the light emitting diode (LED) as a safe and economical irradiation source. The proposed systems are based on coumarins which act as remarkable photoinitiators/photosensitizers (PIs/PSs) combined with N-phenylglycine (NPG) and/or iodonium salt (Iod) as co-initiators in order to generate the reactive species (radicals) that will initiate the photopolymerization recation. Investigation of the chemical mechanisms suggested by the different interactions that take place as well as the photophysical and photochemical properties of coumarins are provided. The access 2 to high polymerization rates (Rp), excellent photoinitiating abilities and great reactive function conversions (FC) is possible with these structures based on the coumarin core. Coumarins show high efficiency for the FRP of (meth)acrylates by reaction with iodonium salt (a photo-oxidation process) or with amine (a photo-reduction process). These compounds were used in 3D printing resins but also for the preparation of photocomposites. In this latter case, an excellent depth of cure was noted as remarkable behavior. To rationalize the experimental results, a kinetic model for a three-component system has been established to analyze the role of oxygen in the monomer conversions and the conversion enhancement observed while using an amine as a co-initiator.

The improvement of catalytic efficiency of catalyst is a challenging topic especially for solid catalyst that has restrained surface to contact reactants. Herein, we reported an effective way to improve the catalytic efficiency by designing composites catalyst (to induce synergistic effect) and performing the reaction under united technologies (to make cooperative contribution). As a model case, La–Fe–O mixture (abbreviated as LFO) and graphitic carbon nitride (abbreviated as g-CN) composites (LFO@CN-n, where n means the molar ratio of the precursors of LFO to g-CN) were synthesized and used as photo-Fenton catalysts for oxidation removal of dyes in wastewater. Results showed that LFO@CN-16, with g-CN loading of 69%, has the properties of both LFO and g-CN, and exhibits high efficiency for dyes oxidation in the presence of H2O2 and light irradiation, with 98% rhodamine B conversion within 25 min, for example. Mechanistic studies suggested that •OH radicals produced from H2O2 are the reaction intermediates, which participate both in the Fenton- and the photo-catalytic processes. Moreover, the catalyst can be reused for at least 5 cycles with no appreciable loss of activity, and can be applied to various organic dyes containing benzene-like cyclic structures with high efficiency.

Construction of photoactive nanofibrous membranes for effective treatment of dyeing effluents is critical to meet the great demands of environmental protection in textile industry, yet still remains a big challenge. In this work, we report a cost-effective strategy to create rechargeable photoactive cellulose nanofibrous membranes (BPTCD-CeNM) under mild conditions that can effectively and repeatedly produce hydroxyl radicals for dye degradation. The principle of this design is that BPTCD-CeNM could store photoactivity under UV light irradiation and release hydroxyl radicals under dark conditions. The membranes possess an ultra-fine fiber diameter (275 nm), large surface area (3.06 m2 g−1) and excellent degradation performance for reactive red 195, reactive yellow 4 and acid blue 7 (> 99.99% within 60 min). The successful fabrication of such materials may open up new avenues for designing and constructing highly efficient photoactive membrane materials for environmental applications.

Green chemistry is developing to invent new reactions that are cheaper, cleaner and use less energy. Acetalization is a common strategy for the protection of aldehydes in synthetic chemistry, yet actual protocols of acetals synthesis are limited by difficult workups, the use of high-loading catalyst, harsh reaction conditions, and catalyst tedious preparation. Alternatively, photocatalysis allows to access functional products with minimum synthetic procedures and waste generation. Here we use sodium 4-[6-(diethylamino)-3-(diethyliminio)-3H-xanthen-9-yl]benzene-1,3-disulfonate (acid red 52) as photocatalyst under yellow light irradiation. We obtained a wide array of acyclic and cyclic acetals in 75–93% yields. Results show the efficient acetalization of aldehydes with alcohols at room temperature, the use of abundant and sustainable alcohols as both the solvents and coupling agents, low catalyst loading, short reaction time, and readily available catalyst, which might be applied to green-catalyzed systems.

Highly ordered Ag2S/ZnS/ZnO nanorod array film photoanodes were prepared on a Ti substrate for photocathodic cathodic protection. The results indicated that the photoresponse range of the Ag2S/ZnS/ZnO composite film was extended compared to those of the ZnO and ZnS/ZnO films, indicating its higher light absorption capacity. When the Ag2S/ZnS/ZnO composite film served as a photoanode, the film can provide the best effective photocathodic protection for 304 stainless steel in a 3.5 wt% NaCl solution under white light illumination compared to the ZnO and ZnS/ZnO films. Additionally, in comparison to pure ZnO film, the photocurrent for the ZnS/ZnO film remained the same without noticeable fluctuation after illumination for 1 h, indicating that the ZnS functionalization improved the stability by overcoming the photocorrosion effect of the ZnO photoanode under light irradiation.

Conversion of alkynes to alkenes by photocatalysis has inspired extensive interest, but it is still challenging to obtain both high conversion and selectivity. Here we first demonstrate the photocatalytic conversion of phenylacetylene (PLE) to styrene (STE) with both high conversion and selectivity by using the titania (TiO2) supported platinum (Pt) as photocatalyst under 385 nm monochromatic light irradiation. It is demonstrated that the conversion rate of PLE is strongly dependent on the content of Pt cocatalyst loaded on the surface of TiO2. Based on our optimization, the conversion of PLE and the selectivity towards STE on the 1 wt% Pt/TiO2 photocatalyst can unexpectedly reach as high as 92.4% and 91.3%, respectively. The highly selective photocatalytic hydrogenation can well be extended to the conversion of other typical alkynes to alkenes, demonstrating the generality of selective hydrogenation of C≡C over the Pt/TiO2 photocatalyst.

Co-existing substances (substances not targeted for degradation) can negatively affect wastewater treatment process performance. Here, we quantitatively evaluated the effects of propanal, a common co-existing substance, on the degradation of the azo-dye Orange II, a common pollutant, by the Fenton process to provide data for the development of measures to reduce the effects of co-existing substances on this wastewater treatment process. Inhibition rate (IR; ratio of the reaction rate constants obtained in the absence and presence of propanal) was calculated to examine the effects of propanal on the degradation of Orange II. The IRs for the Fenton process in the first phase and the second phase were 1.6 and 4.2, respectively. However, addition of ultraviolet irradiation to the Fenton process (i.e., the photo-Fenton process) resulted in a comparable IR for the first phase but a markedly lower IR for the second phase. We attributed this to the improvement of the photo-reduction reaction rate due to complexation of propanal with ferric ions, which compensated for the scavenger effects (the trapping of OH radicals) of propanal. Thus, ultraviolet irradiation reduced the inhibitory effects of propanal on the degradation of Orange II by the Fenton process.

Despite the diverse roles of singlet oxygen (1O2) in plants and animals, simple detection of 1O2 has been limited due to technical difficulties. Here we report a colorimetric method for visualizing the generation and suppression of 1O2 using a protein photo-sensitizer, mini singlet oxygen generator (miniSOG). Upon external light irradiation, miniSOG strongly produced 1O2 and oxidized a universal chromogenic reagent, tetramethylbenzidine, leading to a rapid color change in solution. We used this finding to demonstrate the 1O2 scavenging effects of well-known anti-oxidants and of natural compounds extracted from plants. Owing to its high usability and simplicity, our developed assay platform will be useful for screening potential scavengers for reactive oxygen species and will promote the development of various antioxidants.

In comparison with the Co analog, small Fe clusters incorporated in a graphene matrix exhibit a photo-assisted increase of 110% in reverse water gas shift COhydrogenation under UV-Vis light irradiation. Available data indicate that the photo-assistance derives from light absorption by the N-doped graphene followed by charge recombination at the Fe clusters, increasing their local temperature., Financial support by the Spanish Ministry of Science and Innovation (RTI2018-98237-CO2-1) and Generalitat Valenciana (Prometeo 2017-083) is gratefully acknowledged. This project has also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 861151.

In this paper, the microwave characteristics of typical photosensitive material InP under different light irradiation are studied. The measurement sensor is a reflection-type hemispherical quasi-optical resonator with an operating frequency range from 20 to 40 GHz, an operating mode of TEM00q, and a quality factor of 18,000 or more. For the short-time irradiation experiment, the variation of InP microwave characteristics with the irradiation power of 20 mW, 60 mW, 100 mW, and 200 mW, is studied by frequency-domain and time-domain scanning methods, respectively. The measurement results indicate that the microwave characteristics of InP change significantly even under weak light irradiation. Taking 100 mW and 200 mW irradiation power as examples, the long-time irradiation experiment performed on InP lasting 1.5 min is carried out. The measurement result curves clearly show the influence of the thermal and non-thermal effects on the InP microwave characteristics at the instant of the monochrome light source opening and closing and during irradiation. Furthermore, the temperature distribution of InP during 200 mW irradiation is real-time imaged by a thermal infrared imager to verify the existence of thermal effect during irradiation. The measurement results are in good agreement with the theoretical analysis. The microwave properties of InP under short-time and long-time irradiation are analyzed by frequency-domain and time-domain scanning methods, especially the effects of thermal and non-thermal on microwave properties during long-term irradiation.

Herein, a novel integrated adsorption–photoreduction system, which captures highly mobile and toxic hexavalent chromium (Cr(VI)) from real-world water samples and reduces it to less mobile and benign Cr(III) species, was designed. To do this, a known Zr-MOF, UiO-66, was functionalized with double amino groups. This modification permits the new material, Zr-BDC-(NH2)2, to play a dual-purpose as both adsorbent and photocatalyst. Next, Zr-BDC-(NH2)2 was incorporated into MOF@polymer beads (M@PB) using polyethersulfone (PES) that was chemically modified with carboxylic acid groups to improve hydrophilicity. The modification enhances the Cr(VI) extraction rate of the beads by a factor of ∼3 when compared to the unmodified counterpart. In addition, Zr-BDC-(NH2)2@PB offers one of the highest Cr(VI) uptake capacities reported to date, rapid extraction rates, high selectivity for Cr(VI) in real-world water samples, and full recyclability. The adsorption and subsequent regeneration cycles are carried out in a glass column equipped with a visible light source, demonstrating that the Cr(VI) concentration is brought below drinkable levels, and the Cr(VI) subsequently photoreduced to Cr(III) species using light irradiation during adsorbent regeneration. To the best of our knowledge, this is the first demonstration of MOF-based adsorption–photoreduction of Cr(VI) in a single process.

Understanding the effect of various environmental factors on the transformation of silver nanoparticles (Ag NPs) is crucial to determine their toxicity and fate in the environment. Ag NPs are inevitably exposed to sunlight and will be in contact with chloride (Cl−), a ubiquitous ligand in natural water, once released into the environment. In this study, the combined effect of Cl− and light on various physicochemical properties (optical property, dissolution, morphology, surface charge) of different sizes Ag NPs was studied. The results showed that light irradiation, in the presence of Cl−, led to a great decrease in the concentration of dissolved Ag and a remarkable increase in the zeta potential of Ag NPs, as well as the generation of some tiny Ag NPs and fusion aggregates. AgCl was suggested to rapidly coat onto Ag NPs after exposure to Cl−. And the AgCl layer was obviously destroyed by photoreduction under light irradiation. Meanwhile, the Ag NP size exhibited a great impact on the destruction of the AgCl layer. It was further observed that the AgCl layer gradually re-formed when the light was removed, which suggested that Ag NPs might present different states during the daytime and at night in aquatic environments.

Smart surfaces with special wettability properties have attracted remarkable attention due to the potential for extensive applications in liquid manipulation techniques. However, the challenges in lubricant-wastage and the programmable droplet sliding pathway remain. Here, a silicon oil-infused porous slippery surface was fabricated with UV-responsive controllable wettability (UVRS), and then, the UVRS was integrated with a non-UV-responsive slippery surface (NUVRS) to form composite UV-responsive surfaces (CUVRSs). Due to the conformational transformation of the azobenzene groups under UV light irradiation, the lubricant lost from the surface could be self-replenished, eventually rebuilding a new lubricant layer to re-form the slippery surface. Besides, the color of the exposed surface changed simultaneously, thus providing a new way to monitor the wettability changes and droplet sliding route. By adjusting the design of the “cutting patterns” on NUVRSs and the pattern of the UV masks, the droplet-guiding channels could be programmed orderly. In addition, these programmable droplet pathways could not only be used for point-to-point liquid transportation but also for constructing tailored microfluidic- and micro-reactors. These findings provide a novel way to rebuild smart slippery surfaces and design programmable droplet sliding pathways, thus advancing the application of intelligent slippery surfaces in liquid manipulation, microfluidics and micro-reactor settings.

We report an effective strategy for improving the electronic transport and switching behaviors of dimethyldihydropyrene/cyclophanediene (DHP/CPD)-based molecular devices, an intriguing photoswitch that can be triggered by ultraviolet/visible (UV-vis) light irradiation. Aiming to obtain molecular devices with high on-off ratios, we assess a series of molecular designs formed by [e]-fusing different arenes on a conjugated macrocycle to modulate the photochemical and electronic properties. Here, the switching mechanism and transport properties of [e]-fused DHP/CPD-based nanojunctions are theoretically investigated by first-principles calculations. As a result, the large diversity in electrical conductance between the closed and open forms certifies the substantial switching behavior observed in these sandwich structures. The maximum on-off ratios in all designed photoswitches are greater than 102. Further analysis confirms the improvement of switching performance caused by [e]-fusion. Notably, in the benzo-fused molecular junctions, the maximum on-off ratio is up to 103, which is 55 times larger than that of the un-fused one. We also find that the position of the switch core can remarkably affect the performance of photoswichable nanodevices.

Ultrasmall silver nanoclusters (Ag NCs) with rich surface chemistry and good biocompatibility are promising in antibacterial application, however, further development of Ag NCs for practical settings has been constrained by their relatively weak antibacterial activity. Using the nutritionally-rich medium for bacteria (e.g., Luria-Bertani (LB) medium) to coat active Ag NCs could further improve their antibacterial activity. Here, we provide a delicate design of a highly efficient Ag NCs@ELB antibacterial agent (ELB denotes the extract of LB medium) by anchoring Ag NCs inside the ELB species via light irradiation. The as-designed Ag NCs with bacterium-favored nutrients on the surface can be easily swallowed by the bacteria, boosting the production of the intracellular reactive oxygen species (ROS, about 2-fold of that in the pristine Ag NCs). Subsequently, a higher concentration of ROS generated in Ag NCs@ELB leads to enhanced antibacterial activity, and enables to reduce the colony forming units (CFU) of both gram-positive and gram-negative bacteria with 3–4 orders of magnitude less than that treated with the pristine Ag NCs. In addition, the Ag NCs@ELB also shows good biocompatibility. This study suggests that surface engineering of active species (e.g., Ag NCs) with nutritionally-rich medium of the bacteria is an efficient way to improve their antibacterial activity.

The combination of 3% sodium hyaluronate (HA) and 4% sodium chondroitin sulfate (CS) is used as a dispersive ophthalmic viscosurgical device (OVD) during cataract surgery. For most OVDs containing HA, storage at 2–8 °C is recommended to preserve product characteristics. In order to develop a dispersive OVD that can be stored at room temperature, in this study, we searched additives which can stably maintain the viscosity, a key parameter of OVD, under preservation stability testing at 60 °C. The addition of D-sorbitol to a combination OVD, 3% HA and 4% CS, suppressed the reduction in viscosity compared with other OVDs with or without additives. The addition of D-sorbitol was also effective in improving the residual viscosity of the combination OVD after thermal treatment and light irradiation. Moreover, the OVD containing D-sorbitol can be stored at 25 °C with stably maintaining the initial viscosity for at least 24 months. In conclusion, the new dispersive OVD, 3% HA, 4% CS, and 0.5% D-sorbitol, can be stored at room temperature instead of under cold conditions and may represent an attractive option for clinical use because it is not necessary to bring the product to room temperature prior to use.

Herein, we investigate the effect of the surface attachment of gold nanoparticles (AuNPs) on photosensitiser-entrapped organically modified silica (ormosil) nanoparticles for enhanced photodynamic therapy (PDT). Photosensitiser methylene blue (MB)-entrapped ormosil nanoparticles of three different diameters (30/55/80 nm) were synthesised, and AuNPs were attached to their surface. Subsequent light irradiation with a 630 nm laser resulted in the production of singlet oxygen (1O2), with different amounts depending on the diameter of the ormosil nanoparticle. Enhancement in 1O2 production was observed upon the AuNP attachment on the ormosil surface. In vitro studies in pancreatic cancer (Panc-1) cells have demonstrated that cellular uptake and photodynamic cytotoxicity are also dependent on the size of ormosil nanoparticles and AuNP attachment. These studies pave the way for designing ormosil nanoparticles with suitable size and surface attachment for PDT applications.

Hierarchical hollow CeVO4 microspheres with average size about 5 μm and the thickness of shell walls about 500 nm were fabricated via a simple hydrothermal method with l -Aspartic acid ( l -Asp) as the structure-directing agent. SEM results indicate that hierarchical hollow CeVO4 microspheres are assembled by numerous nanoflakes with thickness of 30–40 nm. The dimensions and hollowness of the hollow microspheres can be tailored via the appropriate controlling of reaction time and the amount of l -Asp. N2 adsorption-desorption measurements revealed the BET surface area of the nanoflakes-assembled CeVO4 hollow microspheres was 98.24 m2/g. The photocatalytic properties of CeVO4 were investigated by the degradation of methylene orange (MO) under UV light irradiation. This excellent performance can be ascribed to the synergistic effect of hollow nature and hierarchical structures, which endowing CeVO4 great potential for purifying organic pollutants.

Ultraviolet (UV) light irradiation is the latest disinfection method and TiO2 is a well-known photocatalyst to generate reactive oxygen species. With the newly emerging UV-LEDs, however, the study of UV-LED/TiO2 photocatalytic disinfection is still rear. In this work, by using Escherichia coli (E. coli) as a model microbe, UV-LED photolytic and UV-LED/TiO2 photocatalytic disinfections were conducted under diverse conditions to examine their inactivation efficiency, repression potential on the repair of bacteria after UV inactivation and the electrical energy consumption. The results showed that increasing the irradiance enhanced the inactivation of E. coli in both photolysis and photocatalysis, especially the former. For a given irradiance of 0.49 mW/cm2 from the 365 nm UV-LEDs, 1.0 g/L was found to be the optimal TiO2 concentration. Then, the dependence of disinfection on wavelengths (265, 275, 310 and 365 nm) was studied at an irradiance of 0.49 mW/cm2 with 1.0 g/L TiO2. The highest inactivation efficiency was achieved by the 265 nm followed by the 275 nm UV-LEDs in both photolytic and photocatalytic disinfection. For these two wavelengths, the addition of 1.0 g/L TiO2 can significantly repress the E. coli repair, whereas the inactivation efficiency becomes slightly worse. On the other hand, when irradiated by wavelengths of 310 and 365 nm, both inactivation efficiency and suppression of repair were significantly improved. Either with TiO2 or not, the irradiation by 275 nm exhibited higher inactivation efficiency. Taking into full consideration of inactivation efficiency, suppression of repair and power consumption, the 275 nm UV-LED/TiO2 was suggested to be a promising option for water disinfection.

In this work, we successfully synthesized a series of CdS-BiOCl/PAN composites by two-step method including electrospinning process and hydrothermal process. The CdS-BiOCl/PAN composites showed great photocatalytic performance and chemical stability for H2 production under UV–vis light irradiation due to the synergistic effect among CdS, BiOCl and PAN. Meanwhile, the content of CdS in CdS-BiOCl/PAN composites plays an important role in photo-catalytic abilities. In addition, according to the analysis about the photocatalyst, the possible photocatalytic mechanism and synergistic interaction were further discussed.

Summary Inspired by astonishing collective motions and tactic behaviors in nature, here we show phototactic flocking of synthetic photochemical micromotors. When enriched with hydroxyl groups, TiO2 micromotors can spontaneously gather into flocks in aqueous media through electrolyte diffusiophoresis. Under light irradiation, due to the dominant nonelectrolyte diffusiophoretic interaction resulting from the overlap of asymmetric nonelectrolyte clouds around adjacent individuals, these flocks exhibit intriguing collective behaviors, such as dilatational negative phototaxis, high collective velocity, and adaptive group reconfiguration. Consequently, the micromotor flocks can migrate along pre-designed paths and actively bypass obstacles with reversible dilatation (expansion/contraction) under pulsed light navigation. Furthermore, owing to the enhanced driving force and rapid dilatational area covering, they are able to execute cooperative tasks that single micromotors cannot achieve, such as cooperative large-cargo transport and collective microenvironment mapping. Our discovery would promote the creation of reconfigurable microrobots, active materials, and intelligent synthetic systems., Graphical Abstract, Highlights • TiO2 micromotors with rich hydroxyl groups can spontaneously gather into flocks • The flocks exhibit dilatational negative phototaxis and adaptive reconfigurations • The flocks can migrate along pre-designed paths and actively bypass obstacles • The flocks can execute cooperative cargo transport and collective mapping, Chemistry; Catalysis; Nanoparticles

Herein we present emission color-tunable and multi-functional lanthanide(III) luminescent hybrid materials (Ln(DPA)@AC-CDs) by mixing aminoclay (AC), 2,6-pyridinedicarboxylic acid (DPA), Ln3+ (Ln = Eu, Tb or Eu and Tb in different molar ratios), and carbon dots (N,S-CDs) in water, showing high quantum yields up to 58.8%. The emission colors can be finely tuned by altering the excitation wavelength and the amounts of the components, and white light emission (CIE-(0.27, 0.25)) can be achieved for sample Eu1Tb2(DPA)@AC-CDs under 325 nm light irradiation. In addition, under 365 nm UV light excitation, the Eu(DPA)@AC-CDs powder exhibits red luminescence due to the sensitization effect of N,S-CDs on Eu3+, which turns to bright blue when the powder is dispersed in water attributed to the high dispersion of the aggregated N,S-CDs particles. These luminescent properties afford Ln(DPA)@AC-CDs potential candidates for designing optoelectronic devices like WLEDs or in information encryption applications.

Nanoscale porphyrinic metal-organic frameworks (NMOFs) have emerged as promising therapeutic platforms for the photodynamic therapy (PDT) of cancer in recent years. However, the relatively large sizes of current NMOFs ranging from tens to hundreds of nanometers usually lead to inefficient body clearance and unsatisfactory PDT effect, thus amplifying their long-term toxicity and restricting their further usage. To overcome these shortcomings, herein, ultrasmall porphyrinic metal-organic framework nanodots (MOF QDs) prepared from NMOFs are rationally synthesized via a facile method and used as renal-clearable nanoagents for the enhanced PDT of cancer. Compared with the precursor NMOFs, our well-prepared MOF QDs can generate 2-fold effective toxic reactive oxygen species (ROS) upon the same light irradiation and greatly decrease the inefficacy of PDT caused by the inefficient use of ROS generated from the interior of NMOFs. Meanwhile, the IC50 value of ultrasmall MOF QDs is nearly one-third that of NMOFs, and in vivo results demonstrate that our MOF QDs exhibit better PDT efficacy than NMOFs under the same treatment owing to their overcoming the limited ROS diffusion distance. Significantly, these ultrasmall MOF QDs show efficient tumor accumulation and rapid renal clearance in vivo, indicating their potential in biomedical utility. Last but not least, comprehensive investigations of long-term toxicity of these MOF QDs well demonstrate their overall safety. Therefore, this study will offer valuable insight into the development of safe and high-performance PDT nanoplatforms for further clinical translation.

Recently, hybrid solar cell that consists of a combination of organic and inorganic materials offers promise in increasing efficiency. Combination of conjugated polymer of Poly (3-hexyl thiophene)/P3HT which has the highest hole mobility with inorganic materials which has high electron mobility, good physical and chemical stability of inorganic nanocrystals, shows a better performance of hybrid solar cells. We have conducted a measurement to investigate the charge carrier transport in active material of hybrid solar cells by using muon spin relaxation (μSR) with light irradiation. A bulk sample used in this study is hybrid organic-inorganic material consisting of regio-regular P3HT and ZnO nanoparticles. Longitudinal-field μSR measurements were performed in magnetic field ranging from 0 to 395 mT at temperature of 10 K, 15 K and 25 K. Based on μSR measurement with light irradiation, we found that for those temperatures, longitudinal field dependence of λ1 was proportional with C-H0.5 curve indicating three-dimensional inter-chain diffusion. We assume that light irradiation initiates the production of exciton that increases the number of charge carrier in the sample and transports not only along the chain of polymer (one-dimensional) but also perpendicular to other chain of polymer (three-dimensional). With light irradiation, the crossover temperature from one-dimensional to three-dimensional of regio-regular P3HT and ZnO nanoparticles bulk sample was obtained at lower temperature of 10 K compared to previous result at 25 K without light irradiation.

The effect of multidimensional heterostructures on charge transfer and charge separation is intriguing in photocatalytic applications. Herein, NiS/ZnIn2S4 heterostructures with tailorable composition, tunable light absorption, and controllable band gap were successfully prepared by a two-step method to show uniform NiS nanoparticles with an average size of 10 nm loaded homogeneously on porous ZnIn2S4 nanosheets. Consequently, NiS/ZnIn2S4 heterostructures have markedly enhanced light absorption and efficient photocatalytic efficiency, reaching the hydrogen evolution rate of 5.0 μmol h−1 under the light irradiation at 420 nm, to be approximately three times higher than that of pure ZnIn2S4. The enhanced photocatalytic efficiency results from faster charge transfer and more efficient photogenerated electron-hole separation under beneficial band alignment. The results shed light on how the photocatalytic reaction occurs at the interface between NiS and ZnIn2S4, and can open a new avenue for synthesizing efficient photocatalysts.

Luminescent oxygen sensor composed of platinum-porphyrin and a gas-permeable polymer binder was applied as an optical crack sensor paint for infrastructure. The sensor paints were designed as a three-layered structure in which the luminescent oxygen sensor layer was sandwiched between oxygen barrier layers. The sensor paints emitted intense luminescence under UV light irradiation, and the luminescence was efficiently quenched when a new crack formed on the concrete surface. Microcracks, which were

In this study, photocatalytic coatings have been prepared by the sol-gel method and applied by spraying on glazed ceramic tiles. This coating has been applied on the tile surface at 400 °C as double firing for 1 h. At this temperature, the coating holds on the surface stronger and at the same time, the anatase form has not been transformed. The coating composition prepared for production scale and the solution were applied in the tile production line. The structural and morphological properties of the coated tiles were investigated and all results were compared with the uncoated tiles. The photocatalytic performance was carried out by the decomposition of methylene blue solution under UV light irradiation. This coating exhibits extremely high photocatalytic activity and it has been taken to production.

Atmospheric NO is one of the toxic and hazardous gases. Its’ levels are continually rising in recent years. As we known, mineral particles contained in the atmosphere may affect the photocatalytic NO removal process. In this study, we found that celestite modification could greatly improve the activity (about 3.8 times) and stability of g-C3N4 for the photocatalytic NO removal. In our system, celestite particles embed in the N vacancies of g-C3N4. The synergistic effect of celestite and N vacancy is the origin of improved NO removal activity. During the light irradiation, photogenerated electrons can be captured and confined by N vacancy. Meanwhile, celestite can transfer these confined electrons to O2 and produce more ·OH, which could oxidize NO to nitrate. These findings can help us to understand the influence of mineral particles in the photocatalytic NO removal and design highly efficient NO removal phtocatalysts.

Three different experiments were performed in order to determine the mechanism of pillars formation using four-beam interference lithography. The experimental results demonstrate that pillars, fabricated in argon gas, were wider and higher compared with the pillars fabricated in nitrogen gas, low vacuum or air. It clearly indicates that the pillar bottom widening effect is not affected by the depletion of atmospheric oxygen as in all environments the fabricated pillars have a wider bottom part. Moreover, the shape of the fabricated pillars is not affecting by the back reflection from the positioning stage and by the light irradiation conditions. These results clearly indicate that the photopolymerization process is enhanced by the heat current and it determines the pillar bottom widening effect.

Combinations of semiconductor nanoparticles (NPs) with noble metal NPs enable an increase in the photoactivity of semiconductor NPs into the visible and near-infrared regions. The design ra...