In this work, uniform molybdenum disulfide (MoS2)/tungsten disulfide (WS2) quantum dots are synthesized by the combination of sonication and solvothermal treatment of bulk MoS2/WS2 at a mild temperature. The resulting products possess monolayer thickness with an average size about 3 nm. The highly exfoliated and defect‐rich structure renders these quantum dots plentiful active sites for the catalysis of hydrogen evolution reaction (HER). The MoS2 quantum dots exhibit a small HER overpotential of ≈120 mV and long‐term durability. Moreover, the strong fluorescence, good cell permeability, and low cytotoxicity make them promising and biocompatible probes for in vitro imaging. In addition, this work may provide an alternative facile approach to synthesize the quantum dots of transition metal dichalcogenides or other layered materials on a large scale.

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The trade‐off between the open‐circuit voltage (Voc) and short‐circuit current density (Jsc) has become the core of current organic photovoltaic research, and realizing the minimum energy offsets that can guarantee effective charge generation is strongly desired for high‐performance systems. Herein, a high‐performance ternary solar cell with a power conversion efficiency of over 18% using a large‐bandgap polymer donor, PM6, and a small‐bandgap alloy acceptor containing two structurally similar nonfullerene acceptors (Y6 and AQx‐3) is reported. This system can take full advantage of solar irradiation and forms a favorable morphology. By varying the ratio of the two acceptors, delicate regulation of the energy levels of the alloy acceptor is achieved, thereby affecting the charge dynamics in the devices. The optimal ternary device exhibits more efficient hole transfer and exciton separation than the PM6:AQx‐3‐based system and reduced energy loss compared with the PM6:Y6‐based system, contributing to better performance. Such a “two‐in‐one” alloy strategy, which synergizes two highly compatible acceptors, provides a promising path for boosting the photovoltaic performance of devices.

Manipulating charge generation in a broad spectral region has proved to be crucial for nonfullerene‐electron‐acceptor‐based organic solar cells (OSCs). 16.64% high efficiency binary OSCs are achieved through the use of a novel electron acceptor AQx‐2 with quinoxaline‐containing fused core and PBDB‐TF as donor. The significant increase in photovoltaic performance of AQx‐2 based devices is obtained merely by a subtle tailoring in molecular structure of its analogue AQx‐1. Combining the detailed morphology and transient absorption spectroscopy analyses, a good structure–morphology–property relationship is established. The stronger π–π interaction results in efficient electron hopping and balanced electron and hole mobilities attributed to good charge transport. Moreover, the reduced phase separation morphology of AQx‐2‐based bulk heterojunction blend boosts hole transfer and suppresses geminate recombination. Such success in molecule design and precise morphology optimization may lead to next‐generation high‐performance OSCs.

Flowerlike gold nanoparticles (Au NPs)/reduced graphene oxide (RGO) composites were fabricated by a facile, one-pot, environmentally friendly method in the presence of regenerated silk fibroin (RSF). The influences of reaction time, temperature, and HAuCl(4): RGO ratio on the morphology of Au NPs loaded on RGO sheets were discussed and a tentative mechanism for the formation of flowerlike Au NPs/RGO composite was proposed. In addition, the flowerlike Au NPs/RGO composite showed superior catalytic performance for oxygen reduction reaction (ORR) to Au/RGO composites with other morphologies. Our work provides an alternative facile and green approach to synthesize functional metal/RGO composites.

Boron nitride quantum dots are obtained by a facile sonication-solvothermal technique. They are proven to be promising fluorescent bioimaging probes for bioimaging with remarkably low cytotoxicity and easily integrated into high-performance proton exchange membranes. This work will probably trigger research interest in BN and its new applications in a variety of fields.

Fused-ring electron acceptors (FREAs) have recently received intensive attention. Besides the continuing development of new FREAs, the demand for FREAs featuring good compatibility to donor materials is becoming more and more urgent, which is highly desirable for screening donor materials and achieving new breakthroughs. In this work, a new FREA is developed, ZITI, featuring an octacyclic dithienocyclopentaindenoindene central core. The core is designed by linking 2,7-dithienyl substituents and indenoindene with small methylene groups, in which the indeno[1,2-b]thiophene-2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile part provides a large and unoccupied π-surface. Most notably, ZITI possesses an excellent compatibility with commercially available polymer donors, delivering very high power conversion efficiencies of over 13%.

reveal the bright future of this greenenergy technology. [1][2][3] Exciton dissociation into free charges is the most important optoelectronic process, which is driven by the energy-level difference between donor and acceptor materials. [4,5] For OSCs utilizing fullerene derivatives as electron acceptors, a lowest unoccupied molecular orbital (LUMO) offset [ΔE LUMO = E LUMO(D) − E LUMO(A) ] of no less than 0.30 eV was generally proposed to guarantee efficient electron transfer. [6][7][8] However, this leads to large energy losses (>0.60 eV), as defined by E loss = E g opt − qV oc , (E g opt is the optical bandgap, V oc is the open-circuit voltage, and q is elementary charge), and limits the power conversion efficiency (PCE) to less than 12% [9][10][11][12][13][14] after decades of effort. Thus far, the development of donor (D)-acceptor (A)-type nonfullerene molecular acceptors (NFAs) with well-tunable electronic structures has opened up a great opportunity in this active topic because these NFAs have realized high PCEs over 15%. [15][16][17][18][19][20][21] To form a complementary absorption, current popular NFA OSCs are based on the combination of a widebandgap donor and a narrow-bandgap acceptor. [22][23][24][25][26][27][28][29][30][31][32][33] For such a material combination, a large ΔE LUMO always exists, which reduces the highest occupied molecular orbital (HOMO) offset [ΔE HOMO = E HOMO(D) − E HOMO(A) ] to minimize energy loss [34][35][36][37] while enhancing the light collection in near-infrared (NIR) Current research indicates that exciton dissociation into free charge carriers can be achieved in material combinations with the highest occupied molecular orbital (HOMO) offset lowered to 0 eV in non-fullerene organic solar cells. However, the quantitative relationship between the HOMO offset and exciton dissociation has not been established because of the difficulty inachieving continuously tunable HOMO offsets. Here, the binary blends of PTQ10:ZITI-S and PTQ10:ZITI-N are combined to form the positive and negative HOMO offsets of 0.20 and −0.07 eV, respectively. While the PTQ10:ZITI-S binary blend delivers a decent power conversion efficiency (PCE) of 10.69% with a shortcircuit current (J sc ) of 16.94 mA cm −2 , the PTQ10:ZITI-N with the negative offset shows a much lower PCE of 7.06% mainly because of the low J sc of 12.03 mA cm −2 . Because the tunable HOMO levels can be realized in organic semiconducting alloys based on ZITI-N and ZITI-S acceptors, the transformation of the HOMO energy offset from negative to positive values is achieved in the PTQ10:ZITIN:ZITI-S ternary blends, delivering much-improved PCEs up to 13.26% with a significant, 74% enhancement of J sc to 20.93 mA cm −2 .With detailed investigations, the study reveals that the minimum HOMO offset of ≈40 meV is required to achieve the most-efficient exciton dissociation and photovoltaic performance.