Photoreforming of lignocellulose is a promising approach toward sustainable H generation, but this kinetically challenging reaction currently requires UV-absorbing or toxic light absorbers under harsh conditions. Here, we report a cyanamide-functionalized carbon nitride, CN, which shows enhanced performance upon ultrasonication. This activated CN allows for the visible-light driven conversion of purified and raw lignocellulose samples into H in the presence of various proton reduction cocatalysts. The reported room-temperature photoreforming process operates under benign aqueous conditions (pH ≈ 2-15) without the need for toxic components.

Two-photon polymerization has been employed to fabricate three-dimensional structures using the biodegradable triblock copolymer poly(epsilon-caprolactone-co-trimethylenecarbonate)-b-poly(ethylene glycol)-b-poly(epsilon-caprolactone-co-trimethylenecarbonate) with 4,4'-bis(diethylamino)benzophenone as the photoinitiator. The fabricated structures were of good quality and had four micron resolution. Initial cytotoxicity tests show that the material does not affect cell proliferation. These studies demonstrate the potential of two-photon polymerization as a technology for the fabrication of biodegradable scaffolds for tissue engineering.

Multiresponsive spiropyran-based random copolymers were synthesized by atom transfer radical polymerization. The polymers were prepared by the copolymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) with the photochromic monomer 1′,3′,3′-trimethyl-6-methacryloyloxyspiro(2H-1-benzopyran-2,2′-indoline) (SP). The solvatochromic, pH, temperature, and light responsive behavior of the PDMAEMA-co-PSP polymers in solution was monitored by UV/vis spectroscopy. The copolymers exhibited “reverse photochromism” and stabilized the planar zwitterionic form of the chromophore, leading to “negative solvatochromism” upon increasing the polarity of the solvent, in contrast to a poly(methyl methacrylate)-co-PSP analogue which stabilized a nonpolar photoisomer and exhibited negligible sensitivity to the polarity of the surrounding medium, before irradiation. Moreover, the PDMAEMA-co-PSP copolymers exhibited a reversible pH-responsive character in aqueous media; the addition of a strong acid induced the SP-to-merocyanine (MC) isomerization, the formation of [MC−OH]+ and [SP−NH]+ species, and the disappearance of the H-type aggregates, whereas the initial SP moieties were recovered in alkaline media. The chromophore content and the photoinduced MC-to-SP isomerization affected the transition temperature of the PDMAEMA-co-PSP polymers. The lower critical solution temperature (LCST) of the copolymers increased with their content in hydrophilic MC moieties, while the MC-to-SP photoinduced isomerization decreased significantly the LCST due to the hydrophobic character of the SP units. Finally, the copolymers exhibited a first-order photoinduced bleaching of the chromophore units in water and acetonitrile, with a slower decoloration rate in the aqueous medium due to the effective stabilization of the bipolar MC form in the polar environment.

This article describes the light-driven supramolecular engineering of water-dispersible nanocapsules (NCPs). The novelty of the method lies in the utilization of an appropriate phototrigger to stimulate spherical polymer brushes, consisting of dual-responsive 2-(dimethylamino)ethyl methacrylate (DMAEMA) and light-sensitive spiropyran (SP) moieties, for the development or disruption of the NCPs in a controlled manner. The fabrication of the nanocarriers is based on the formation of H-type π-π interactions between merocyanine (MC) isomers within the sterically crowded environment of the polymer brushes upon UV irradiation, which enables the SP-to-MC isomerization of the photosensitive species. After HF etching of the inorganic core, dual-responsive polymeric vesicles whose walls' robustness is provided by the MC-MC cross-link points are formed. Disruption of the vesicles can be achieved remotely by applying a harmless trigger such as visible-light irradiation. The hydrophilic nature of the DMAEMA comonomer facilitates the engineering of the vesicles in environmentally benign aqueous media and enables the controlled alteration of the NCPs size upon variation of the solution pH. The inherent ability of the NCPs to fluoresce in water opens new possibilities for the development of addressable nanoscale capsules for biomedical applications.

Photoelectrochemical (PEC) artificial leaves hold the potential to lower the costs of sustainable solar fuel production by integrating light harvesting and catalysis within one compact device. However, current deposition techniques limit their scalability, 1 while fragile and heavy bulk materials can affect their transport and deployment. Here, we demonstrate the fabrication of lightweight artificial leaves by employing thin, flexible substrates and carbonaceous protection layers. Lead halide perovskite photocathodes deposited onto indium tin oxide coated polyethylene terephthalate achieve an activity of 4266 µmol H2 g -1 h -1 using a platinum catalyst, whereas photocathodes with a molecular Co catalyst for CO2 reduction attain a high CO:H2 selectivity of 7.2 under a lower 0.1 sun irradiation. The corresponding lightweight perovskite-BiVO4 PEC devices display unassisted solar-to-fuel efficiencies of 0.58% (H2) and 0.053% (CO), respectively. Their potential for scalability is demonstrated by 100 cm 2 standalone artificial leaves, which sustain a comparable performance and stability of ≈24 h to their 1.7 cm 2 counterparts. Bubbles formed under operation further enable the 30-100 mg cm -2 devices to float, while lightweight reactors facilitate gas collection during outdoor testing on a river. The leaf-like PEC device bridges the gulf in weight between traditional solar fuel approaches, showcasing activities per gram comparable to photocatalytic suspensions and plant leaves. The presented lightweight, floating systems may enable open water applications, while avoiding competition with land use.

Six amphiphilic model conetworks of a new structure, that of cross-linked "in-out" star copolymers, were synthesized by the group transfer polymerization (GTP) of the hydrophobic monomer benzyl methacrylate (BzMA) and the ionizable hydrophilic monomer 2-(dimethylamino)ethyl methacrylate (DMAEMA) in a one-pot preparation. The synthesis took place in tetrahydrofuran (THF) using tetrabutylammonium bibenzoate (TBABB) as the catalyst, 1-methoxy-1-(trimethylsiloxy)-2-methyl-propene (MTS) as the initiator, and ethylene glycol dimethacrylate (EGDMA) as the cross-linker. Three heteroarm star-, two star block-, one statistical copolymer star-, and one homopolymer star-based networks were prepared. The synthesis of these star-based networks involved four to six steps, including the preparation of the linear (co)polymers, the "arm-first" and the "in-out" star copolymers, and finally the network. The precursors and the extractables were characterized using gel permeation chromatography (GPC) and proton nuclear magnetic resonance (1H NMR) spectroscopy. The degrees of swelling (DSs) of all the networks were measured in THF, while the aqueous DSs were measured as a function of pH. The DSs at low pH were higher than those at neutral or high pH because of the protonation of the DMAEMA units and were found to be dependent on the structure of the network. The DSs in THF were higher than those in neutral water and were independent of the structure. Finally, DNA adsorption studies onto the networks indicated that the DNA binding was governed by electrostatics.

A sunlight‐powered process is reported that employs carbon dots (CDs) as light absorbers for the conversion of lignocellulose into sustainable H2 fuel and organics. This photocatalytic system operates in pure and untreated sea water at benign pH (2–8) and ambient temperature and pressure. The CDs can be produced in a scalable synthesis directly from biomass itself and their solubility allows for good interactions with the insoluble biomass substrates. They also display excellent photophysical properties with a high fraction of long‐lived charge carriers and the availability of a reductive and an oxidative quenching pathway. The presented CD‐based biomass photoconversion system opens new avenues for sustainable, practical, and renewable fuel production through biomass valorization.

Efficient and scalable solution-based processes are not generally available to integrate wellstudied pseudocapacitive materials (i.e., metal oxides and conducting polymers) with other components such as porous carbon, mainly because these classes of pseudocapacitive systems have poor solubilities in solvents and exhibit no specific interactions with the other component.Here we report, for the first time, the integration of a metallocene polymer, polyvinylferrocene (PVF), with carbon nanotubes (CNTs) via a simple solution process for supercapacitor applications. The solution processability of the PVF/CNT hybrid is due to the high solubilities of PVF in organic solvents and the unique ability of the metallocene/carbon system to form stable heterogeneous inks through the π-π stacking interactions between the two components. The nanostructure and electrochemical properties of the hybrid can be manipulated systematically by adjusting the composition of the heterogeneous ink. The hybrid with the optimized composition exhibits unusually high capacitance (1452 F/g) and energy density (128.9 Wh/kg) obtained in a standard two-electrode configuration, outperforming previously reported pseudocapacitive materials. Broader ContextSupercapacitors with extremely high capacitance, enhanced energy and power densities, and excellent reliability offer great potential as complements to, and replacements for, batteries and conventional electrolytic capacitors for energy storage applications. Carbon nanomaterials, metal 2 oxides and conducting polymers have been investigated widely as supercapacitor electrode materials. Many emerging high-performance supercapacitor devices benefit from the integration of these different capacitive materials to exploit their synergies for enhanced capacitance and energy density. Meanwhile, solution processing is low-cost, high-throughput, and readily scalable.It is the preferred fabrication method for many devices such as solar cells, transistors, batteries and single-component supercapacitors, but is very difficult to use for the integration of either metal oxides or conducting polymers with other capacitive materials such as carbon nanotubes.Instead, the common integration methods rely for the most part on electrochemical deposition processes, which are time-consuming, low-throughput and difficult to scale up. In this study we have developed a metallocene/carbon hybrid system amenable to solution processing, with control of the nanostructure and electrocapacitive performance of the hybrid materials realized through manipulation of the ink composition. The optimized hybrid system, as determined by its composition, consists of a highly porous nanoscale architecture in which a three-dimensional conductive carbon nanotube network with interconnected nanopores is coated conformally by the redox-active metallocene polymer. This unique morphology simultaneously facilitates electron transport, reduces ion diffusion length, and increases metallocene utilization efficiency. Thus this hybrid exhibits si...