Highly efficient detection in the aqueous phase for water-insoluble organic molecule probes is challenging.T he bright aggregated-state electrochemiluminescence (ECL) of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles by ac o-reactant approach was discovered, and ah eterogeneous aggregationinduced emission ECL (HAIE-ECL) was constructed at the electrode surface,s howing very high ECL efficiency (37.8 %) and selective recognition for industrially important DNBP plasticizer with al ow detection limit of 0.15 nm in the water phase.Am echanistic study indicates that ECL is mainly generated due to the high electron affinity of siloles and restriction of the intramolecular motions caused by their propeller-like noncoplanar structures.T his system realizes the sensing of organic-based ECL in the water phase by solving the crucial problems of water insolubility and aggregationcaused quenching (ACQ), and demonstrates potential for further application because of its design and high efficiency.Scheme 1. Chemical structures of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles and 1,1-dimethyl-3,4-diphenyl-2,5-bis(trimethylsilyl)silole.

The development of highly active, eco-friendly, and structurely fine-tunable organic luminophores is currently desirable for electrochemiluminescence (ECL). Tetraphenylethene (TPE) derivatives are the most representative aggregation-induced emission characteristic (AIEgens). In contrast, their aggregation-induced ECLs have not been detail studied. Herein, we report the bright cathodic aggregated state ECL of TPE derivatives by a coreactant approach. In this system, the substituents profoundly affect ECL emissions by changing the relative intensities of R and B band intensity ratios in their UV–vis spectra as well as the HOMO and LUMO energies. It was discovered that electron-withdrawing nitro-substituted TPE-(NO2)4 with a smaller LUMO/HOMO band gap and stronger R band featured the strongest ECL emissions and became the best luminophore for the highly efficient detection of iodide (I–) in the aqueous phase. This work not only reveals the influence of R and B bands in TPE derivative UV–vis spectra on their optical properties but also constructs a novel aggregation-induced ECL sensing.

By af acile peripheral decoration of 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (ATPP) with inherent aggregation-induced emission (AIE) active tetraphenylethene (TPE), av ersatile AIEgenic porphyrin derivative (ATPP-TPE) was obtained, whichgreatly abolishes the detrimental pp stacking and thus surmounts the notorious aggregationcaused quenching (ACQ) effect of ATPP in aqueous phase. The photoluminescence of ATPP-TPE is 4.5-fold stronger than ATPP at aggregation state.M oreover,a nu nequivocal aggregation induced electrochemiluminescence (AIECL) of ATPP-TPE was found to be seriously dependent on its aggregation property in aqueous solution with efficiency of 34 %, which is 6times higher than pure ATPP.The versatility of this molecular structure modulation strategy along with the ACQ-to-AIE transformation in this work provides direction to guide for applying liposoluble porphyrins in aqueous phase by designs of synthetic porphyrin AIEgens.

Depositing a transition‐metal hydroxide (TMH) layer on a photoanode has been demonstrated to enhance photoelectrochemical (PEC) water oxidation. However, the controversial understanding for the improvement origin remains a key challenge to unlock the PEC performance. Herein, by taking BiVO4/iron‐nickel hydroxide (BVO/FxN4−x‐H) as a prototype, we decoupled the PEC process into two processes including charge transfer and surface catalytic reaction. The kinetic information at the BVO/FxN4−x‐H and FxN4−x‐H/electrolyte interfaces was systematically evaluated by employing scanning photoelectrochemical microscopy (SPECM), intensity modulated photocurrent spectroscopy (IMPS) and oxygen evolution reaction (OER) model. It was found that FxN4−x‐H acts as a charge transporter rather than a sole electrocatalyst. PEC performance improvement is mainly ascribed to the efficient suppression of charge recombination by fast hole transfer kinetics at BVO/FxN4−x‐H interface.

Exploring efficient and robust electrochemiluminescence (ECL) performance of liposoluble porphyrins in aqueous phase for analytical purposes especially for important biological targets is still very challenging. In this work, a novel depolymerization-induced electrochemiluminescence (DIECL) of porphyrin and β-cyclodextrin (β-CD) self-assembly through a coreactant route was discovered. Among the studied meso-tetrasubstituted porphyrins, self-assembly of 5,10,15,20-tetrakis­(4-hydroxyphenyl) porphyrin (THPP) and β-CD (THPP@β-CD) exhibits the best DIECL behavior with high efficiency (21.8%) as well as good reproducibility and stability. A mechanistic study suggests that the facile complexation of porphyrins with amphiphilic β-CD via hydrogen bonding interaction greatly improves the water insolubility and the aggregation-caused deficient ECL of liposoluble porphyrins in aqueous solution. Furthermore, because of the strong hydrogen bonding between the hydroxyl groups on THPP@β-CD and a highly electronegative substrate, such THPP@β-CD is found to serve as an efficient luminophore for recognition of most electronegative fluoride (F–) in the aqueous phase with high sensitivity and selectivity, together with a low limit of detection (0.74 μΜ). The simplicity of this THPP@β-CD and its unique DIECL property in current work provides a new guide for the ECL applications of liposoluble porphyrins in aqueous phase.

Developing a convenient and rapid detection method for water is greatly desirable in the field of chemical industry. Herein, we present a simple and effective strategy combining a fluorescence sensor and a one-to-two fluorescence colorimetric logic operation to monitor water in a wide range of organic media and classify aprotic/protic polar solvents. The dual-emitting luminescent detector was prepared by incorporating a fluorescent dye Rhodamine 6G (R6G) with strong green light emission within a red light-emitting Eu-metal–organic framework (MOF) through the “bottle around ship” method. R6G@Eu-MOF displays completely different fluorescence response behaviors to various organic solvents. Thus, when one made use of the intensity ratio of different fluorescence emission centers, a 3D decoded map was proposed to reliably and effectively distinguish different aprotic/protic polar solvents. Moreover, R6G@Eu-MOF exhibited two different ratiometric sensing modes when detecting water in aprotic/protic polar solvents due to the hydrogen bonding interaction, that is ratiometry with one reference signal or two reversible signal changes. Furthermore, using water content as the input signal and two kinds of fluorescence emission as the output signals, a one-to-two logic gate system was constructed, making it possible to develop an intelligence system for water detection. Overall, we demonstrated for the first time that R6G@Eu-MOF could serve as an efficient platform for tracing water in organic media and distinguishing protic/aprotic polar organic solvents.

Semiconductor/co‐catalyst coupling is considered as a promising strategy to enhance the photoelectrochemical (PEC) conversion efficiency. Unfortunately, this model system is faced with a serious interface recombination problem, which limits the further improvement of PEC performances. Here, a FeNiOOH co‐catalyst with abundant oxygen vacancies on BiVO4 is fabricated through simple and economical NaBH4 reduction to accelerate hole transfer and achieve efficient electron–hole pair separation. The photocurrent of the BV (BiVO4)/Vo‐FeNiOOH system is more than four times that of pure BV. Importantly, the charge transfer kinetics and charge carrier recombination process are studied by scanning photoelectrochemical microscopy and intensity modulated photocurrent spectroscopy in detail. In addition, the oxygen vacancy regulation proposed is also applied successfully to other semiconductors (Fe2O3), demonstrating the applicability of this strategy.

Due to significantly tackling the problems of aggregation-caused quenching and water insolubility, aggregationinduced emission electrochemiluminescence (AIE-ECL) has emerged as a research highlight in aqueous detection and sensing. Herein, we reported a series of cyclopentadienols featuring excellent AIE-ECL properties on the basis of an enhanced aromaticity strategy. In detail, substituents profoundly determined ECL emission by affecting the characteristic absorption peak intensity ratio in UV−vis spectra and lowest unoccupied molecular orbital (LUMO)−highest occupied molecular orbital (HOMO) energies. It was found that 1,2,3,4,5-pentafluorophenyl cyclopentadienol (PFCD) containing an electron-withdrawing fluorine substituent, the maximum R/B band ratio, and a smaller LUMO−HOMO band gap demonstrated the best ECL performance. Meanwhile, such an AIE-ECL system displayed a wide response range toward pH (4−12) with a good linear relationship. Our research not only enriched polycyclic aromatic hydrocarbon-based AIE-ECL systems but also established an efficient pH sensor in the aqueous phase.