Black phosphorus (BP) nanosheet (NS) is an emerging oxygen evolution reaction (OER) electrocatalyst with both high conductivity and abundant active sites. However, its ultrathin structure suffers instability because of the lone pair electrons exposed at the surface, which badly restricts durability for achieving long‐term OER catalysis. Herein, a facile solvothermal reduction route is designed to fabricate Co/BP NSs hybrid electrocatalyst by in situ growth of cobalt nanoparticles on BP NSs. Notably, electronic structure engineering of Co/BP NSs catalyst is observed by electron migration from BP to Co due to the higher Fermi level of BP than that of Co. Because of the preferential migration of the active lone pairs from the defect of BP NSs, the stability and high hole mobility can be effectively retained. Consequently, Co/BP NSs electrocatalyst exhibits outstanding OER performance, with an overpotential of 310 mV at 10 mA cm−2, and excellent stability in alkaline media, indicating the potential for the alternatives of commercial IrO2. This study provides insightful understanding into engineering electronic structure of BP NSs by fully utilizing defect and provides a new idea to design hybrid electrocatalysts.

A highly efficient Pd(OAc)2/guanidine aqueous system for the room temperature Suzuki cross-coupling reaction has been developed. The new water-soluble and air-stable catalyst Pd(OAc)2.(1f)2 from Pd(OAc)2 and 1,1,3,3-tetramethyl-2-n-butylguanidine (1f) was synthesized and characterized by X-ray crystallography. In the presence of Pd(OAc)2.(1f)2, coupling of arylboronic acids with a wide range of aryl halides, including aryl iodides, aryl bromides, even activated aryl chlorides, was carried out smoothly in aqueous solvent to afford the cross-coupling products in good to excellent yields and high turnover numbers (TONs) (TONs up to 850,000 for the reaction of 1-iodo-4-nitrobenzene and phenylboronic acid). Furthermore, this mild protocol could tolerate a broad range of functional groups.

A novel mechanism of folding-induced spin–orbit coupling enhancement is responsible for the efficient room temperature phosphorescence of a thianthrene emitter.

commonly used multicomponent strategy for white-light emitter, SMWLEs possess many attractive and distinctive advantages, such as absent phase separation, minimal color-aging, easy fabrication, good stability, etc. [2] However, the high-efficiency SMWLE has been always a serious scarcity, as a result of the extremely challenging single-molecule mechanism for whitelight emission according to the Kasha's rule. [3] Typically, the simultaneous dual emission or ternary emission is required to make up white-light emission in singlecomponent material, corresponding to two-color (blue and yellow/orange) or three-color (blue, green and red) emissive sources. [4] In terms of the simplest dual-emission strategy, it can be assigned to two emissive excited states: one excited state is responsible for blue emission and the other one contributes to yellow/orange emission. Usually, the former is locally excited (LE) singlet state, while the latter can be the one among charge-transfer (CT) state, [5] excimer state, [6] proton-transfer state, [7] self-assembly state, [8] the lowest triplet (T 1 ) excited state for room-temperature phosphorescence (RTP), [9] and so on. [10] What is more, this dual emission can also be assigned to dual RTP emission, corresponding to the coemission from both T 1 and T 2 states, respectively. [11] With the recent progress of pure organic RTP materials, [12] more and more dual emission of fluorescence and phosphorescence were observed with SMWLE property. However, the efficiency improvement of pure organic SMWLEs from the dual emission of fluorescence and phosphorescence is one of the most challenging issues. This is because that spin-orbit coupling (SOC) in pure organic systems is weak, which can afford neither the effective intersystem crossing (ISC) for triplet exciton generation nor the efficient triplet exciton radiation to surpass all possible nonradiations (e.g., vibrational quenching, oxygen quenching). [13] More importantly, in comparison with multicomponent white-light emitter, the difficulty will be dramatically increased to achieve the simultaneous enhancement of dual emission of fluorescence and phosphorescence. As for the reasons, there are many internal and external factors affecting these two emissive excited states (fluorescence and phosphorescence) and the balance between them due to the Developing the single-molecule white-light emitters (SMWLEs) at room temperature is very challenging for pure organic metal-free system, and it is even more challenging to achieve the high efficiency of pure organic SMWLE. Here, alkoxy substituents are tailored at 2-positioned thioxanthone (TX) to finely tune the molecular packing mode and the intermolecular interaction between TX units, and the photoluminescence (PL) efficiency (Φ PL ) of SMWLE is improved successfully from 1.5% (TX) to 45.0% (TX-OCH(CH 3 ) 2 ). This simultaneous enhancement of dual emission between fluorescence and phosphorescence can be ascribed to i) a moderate intersystem crossing (ISC) rate for the equilibrium distribution b...

A semiconductor fabricated by embedding plasmonic Au nanoparticles into CdS exhibits a high activity and stability for photocatalytic H2evolution. This composite structure could take full advantage of electromagnetic fields at the surface of the Au nanoparticles under visible light illumination.

In order to develop pure organic single-molecule white-light emitters (SMWLE), the oxidation of thianthrene (TA) was performed on sulfur atoms at different degrees to tune room temperature phosphorescence (RTP) emission. With increasing degrees of oxidation from 1OTA, 2OTA, 3OTA, to 4OTA, monomeric and aggregative RTP emission was gradually suppressed, due to the gradual disappearance of lone pair electrons on sulfur atoms. Among these compounds, monomers and aggregates of 1OTA demonstrated a better intensity match between fluorescence and RTP. Through partial oxidation of TA, 1OTA exhibited the simultaneous ternary emissions from the lowest singlet state (S 1 ), the lowest triplet state (T 1 ), and the high-lying triplet state (T n ) in doped film. The single-molecule white-light emission was achieved in 1OTA crystal with a photoluminescence quantum yield (PLQY) of 47.1%. This work not only reports the RTP behavior of TA with different degrees of oxidation, but also provides an example of excited-state modulation to harvest an efficient SMWLE material.

An unusual blue shift in excimer fluorescence with increasing temperature was observed from a crystal with a discrete π–π anthracene dimer.

Bifunctional asymmetric phase-transfer catalysts bearing multiple hydrogen-bonding donors have rarely been explored. The first quaternary ammonium type of these catalysts derived from cinchona alkaloids were readily prepared and found to be highly efficient catalysts for asymmetric nitro-Mannich reactions of amidosulfones. Compared with previous reports, very broad substrate generality was observed, and both enantiomers of the products were achieved in high enantio- and diastereoselectivity (90-99% ee, 13:1 to 99:1 dr).