Photoinduced Charge Transfer Research Articles

Boosted elimination of florfenicol by BiOClxBr1-x solid solutions via photocatalytic ozonation under visible light

In this work, a series of BiOClxBr1-x (BCB) solid solutions are facilely designed for visible-light-driven photocatalytic ozonation (PCO) degradation of florfenicol (FF) in water environments, which could add to the library of efficient, cost-effective and robust nanocatalysts for water purification. BCB solid solutions in the structure of 2D nanosheets are achieved involving the etching of BiOBr “micro-flowers” with HCl at different concentrations, allowing a removal ratio of FF up to 97.3 % within 1 h, superior to bare BiOBr and bare BiOCl. A strengthened synergistic effect between photocatalysis and ozonation is substantiated, where the separation of photo-induced charge transfer is accelerated, the band gap is tuned and the utilization efficiency of ozone is enhanced. This facilitates the production of reactive oxygen species identified as •OH, •O2–, and 1O2 that will attack the FF molecule for degradation based on three pathways.

Hydroxyl-Bonded Ru on Metallic TiN Surface Catalyzing CO2 Reduction with H2O by Infrared Light.

Synchronized conversion of CO2 and H2O into hydrocarbons and oxygen via infrared-ignited photocatalysis remains a challenge. Herein, the hydroxyl-coordinated single-site Ru is anchored precisely on the metallic TiN surface by a NaBH4/NaOH reforming method to construct an infrared-responsive HO-Ru/TiN photocatalyst. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (ac-HAADF-STEM) and X-ray absorption spectroscopy (XAS) confirm the atomic distribution of the Ru species. XAS and density functional theory (DFT) calculations unveil the formation of surface HO-RuN5-Ti Lewis pair sites, which achieves efficient CO2 polarization/activation via dual coordination with the C and O atoms of CO2 on HO-Ru/TiN. Also, implanting the Ru species on the TiN surface powerfully boosts the separation and transfer of photoinduced charges. Under infrared irradiation, the HO-Ru/TiN catalyst shows a superior CO2-to-CO transformation activity coupled with H2O oxidation to release O2, and the CO2 reduction rate can further be promoted by about 3-fold under simulated sunlight. With the key reaction intermediates determined by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and predicted by DFT simulations, a possible photoredox mechanism of the CO2 reduction system is proposed.

Multifunctional Photoelectroactive Materials for Optoelectronic Applications Based on Thieno[3,4-b]pyrazines and Thieno[1,2,5]thiadiazoles.

In this study, we introduce a novel family of symmetrical thiophene-based small molecules with a Donor-Acceptor-Donor structure. These compounds feature three different acceptor units: benzo[c][1,2,5]thiadiazole (Bz), thieno[3,4-b]pyrazine (Pz), and thieno[1,2,5]thiadiazole (Tz), coupled with electron donor units based on a carbazole-thiophene derivative. Using Density Functional Theory (DFT), we investigate how the molecular geometry and strength of the central acceptor unit impact the redox and spectroscopic properties. Notably, the incorporation of Pz and Tz moieties induces a significant redshift in the absorption and emission spectra, which extend into the near-infrared (NIR) region, simultaneously reducing their energy gaps (~1.4-1.6 eV). This shift is attributed to the increased coplanarity of the oligomeric inner core, both in the ground (S0 ) and excited (S1 ) states, due to the enhanced quinoidal character as supported by bond-length alternation (BLA) analysis. These structural changes promote better π-electron delocalization and facilitate photoinduced charge transfer processes in optoelectronic devices. Notably, we show that Pz- and Tz-containing molecules exhibit NIR electrochromic behavior and present ambivalent character in bulk heterojunction (BHJ) solar cells. Finally, theoretical calculations suggest that these molecules could serve as effective two-photon absorption (2PA) probes, further expanding their potential in optoelectronic applications.

In Situ Interfacial Engineering of CeO2/Bi2WO6 Heterojunction with Improved Photodegradation of Tetracycline and Organic Dyes: Mechanism Insight and Toxicity Assessment.

The construction of heterojunction photocatalysts is an auspicious approach for enhancing the photocatalytic performance of wastewater treatment. Here, a novel CeO2/Bi2WO6 heterojunction is synthesized using an in situ liquid-phase method. The optimal 15% CeO2/Bi2WO6 (CBW-15) is found to have the highest photocatalytic activity, achieving a degradation efficiency of 99.21% for tetracycline (TC), 98.43% for Rhodamine B (RhB), and 94.03% for methylene blue (MB). The TC removal rate remained at 95.38% even after five cycles. Through active species capture experiments, •O2 -, h+, and •OH are the main active substances for TC, RhB, and MB, respectively. The possible degradation pathways for TC are analyzed using liquid chromatography-mass spectrometry(LC-MS). The photoinduced charge transfer and possible degradation mechanisms are proposed through experimentation and density functional theory (DFT) calculations. Toxicity assessment experiments show a significant reduction in toxicity during the TC degradation process. This study uncovers the mechanism of photocatalytic degradation in CeO2/Bi2WO6 and provides new insights into toxicity assessment.

Ring‐Opening Coupling Reaction of Cyclopropanols with Electrophilic Alkenes Enabled by Decatungstate as Photoredox Catalyst

AbstractWe introduce a methodology for the photocatalytic generation of β‐ketoalkyl radicals from tertiary cyclopropanols, utilizing tetrabutylammonium decatungstate (TBADT) as a photoredox catalyst. The application is demonstrated by the synthesis of distantly functionalized ketones via the redox‐neutral addition of the cyclopropanol‐derived β‐ketoalkyl radicals to the double bond of electrophilic olefins. The transformation occurs under ambient temperature conditions and is suitable for coupling a wide range of cyclopropanol and alkene substrates. This was demonstrated by the preparation of 33 ketone products with 35–92% yield. The method's preparative robustness has been validated through upscaled preparations conducted under continuous flow conditions. Mechanistic investigations support the role of TBADT as a photoredox catalyst, which facilitates the single electron oxidation of cyclopropanols, followed by the electron transfer from the reduced form of decatungstate to the electrophilic double bond of alkene. Moreover, we found that electron‐rich aromatic cyclopropanols and electron‐deficient olefins form photoactive electron donor‐acceptor (EDA) complexes. This property allows the reaction to proceed under UV light irradiation via the photoinduced charge transfer in the absence of the photocatalyst.

Effect of solvent and thermal annealing on D18/Y6 polymer solar cells

Organic solar cells (OSCs) as emerging generation solar cells are required to face climate and energy challenges. In this regard, OSCs based on the D18:Y6 active layer with a ratio of 1:1.6 with thermal and solvent annealing as a post-treatment were fabricated. The effect of different thermal annealing with chloroform on the active layer and the cell performance was studied. Optical, morphological and thermal analysis are executed to investigate the effect of thermal with solvent annealing on the D18:Y6 active layer. Photoluminescence (PL), transmission electron microscope (TEM) and atomic force microscope (AFM) reveal that D18:Y6 film treated at 55 °C with chloroform for 5.0 min had the lowest PL intensity, interpenetrating grain networking structures and more smoother surface leads to optimize photo-induced charge transfer and exciton dissociation in the active layer. D18: Y6 blend film annealed at 80 °C with chloroform for 5.0 min exhibits higher roughness of 17.81 nm than 11.60 nm for D18:Y6 blend film treated at 55 °C. As a result, the optimal performance of the fabricated conventional OSCs based on active layer treated at 55 °C with chloroform had short-current density (Jsc), open circuit voltage (Voc), fill factor (FF) and efficiency of 60 mA/cm2, 0.70V, 39.8% and 16.5%, respectively. This study indicates additional thermal annealing with chloroform as a post-treatment enhances the device performance of OSCs.Graphical abstractStudying the effect of solvent vapor annealing with thermal annealing of D18:Y6 layer aspost-treatment on the performance of organic solar cells.

Entropy Engineering on 2D Metal Phosphorus Trichalcogenides for Surface‐Enhanced Raman Scattering

AbstractSurface‐enhanced Raman scattering (SERS) spectroscopy is an ultrasensitive detection technique for molecular identification in both biology and chemistry. 2D materials have displayed increasing potentials as SERS substrates based on chemical enhancement, where optimization of the band structure to promote the charge transfer is exceptionally important. Here, the regulation of band structure of 2D metal phosphorus trichalcogenides (MPCh3) via entropy engineering is demonstrated. The optimized high‐entropy MnFeCuAgInPS3 nanosheets (NSs) with narrowed bandgap (Eg) show significant SERS performance with a low detection limit with 10−9 m for both rhodamine 6G and crystal violet. Combined spectral characterizations and density functional theory (DFT) calculations reveal that the combination of multiple hetero‐element provides continuous d orbitals and endows high‐entropy MPCh3 NSs with high population of electrons at the energies near Fermi level (EF), which allows highly efficient photo‐induced charge transfer (PICT) between the SERS substrates and target molecules. This work affords a new strategy for high‐performance 2D SERS materials and also reveals the origin of the band structure regulation by entropy engineering.

Therapeutic drug monitoring mediated by the cooperative chemical and electromagnetic effects of Ti3C2TX modified with Ag nanocubes

It is pivotal for the credible utilization of surface-enhanced Raman scattering (SERS) technique in clinical drug monitoring to exploit versatile substrates with dependable quantitative detection and robust recognition abilities. Herein, a commendable electromagnetic-chemical dual-enhancement SERS substrate dependent on Ti3C2TX and Ag nanocubes (Ag NCs) was fabricated for the precise quantification of ritonavir and ibrutinib in serum. Specifically, it was revealed that numerous electromagnetic “hotspots” emerged nearby the extremely tiny nanogaps among the intimately clustered Ag NCs, which also acted as optimal channels to facilitate effective photo-induced charge transfer (PICT) between the two-dimensional Ti3C2TX matrix and target molecules. The cooperation between electromagnetic and chemical effects yielded a satisfactory enhancement factor (EF) of 4.77 × 107 for the composite substrate. Benefiting from the remarkable sensitivity of the Ti3C2TX/Ag NCs composite substrate, the low limit of detection (LOD) at 10−6 mg/mL was successfully attained, along with exceptional recoveries of exceeding 90% for ritonavir and ibrutinib in serum. Considering its reliability and simplicity, our strategy holds immense promise for its utilization in efficient monitoring and identification of clinical blood drug concentration.

Voltage tuning of photoinduced charge transfer resonances between 2,2′-bipyridine and a nanostructured silver electrode

The effect of applied electric potentials and excitation wavelengths (785, 532, 473 nm) on the Surface-Enhanced Raman scattering (SERS) of 2,2′-bipyridine (2,2′-bpy) adsorbed on a silver electrode has been analyzed on the basis of a charge transfer (CT) resonance mechanism. DFT/TD-DFT calculations performed for a simple model of surface complex (Ag2-2,2′-bpy) point out that 2,2′-bpy preferably adsorbs through both nitrogen atoms in a cis-conformation with edge-on orientation. The calculated spectra in resonance with the two first bright metal-to-molecule charge transfer electronic states (CT0;B1 and CT1;B1) account for the main experimental features: the selective enhancement of the totally symmetric modes recorded at about 1585, 1560 and 1480 cm−1 under 532 nm line, staying the 1560 cm−1 band as the most intense under 473 nm line at more negative electrode potential. The split of SERS bands recorded in the 1600, 1000 and 600 cm−1 regions point to the existence of a monodentate coordination of the cis-conformer. The calculated resonance condition up to CT0 and CT1 states is fulfilled under 532 and 488 nm excitation lines, respectively, agreeing with the behaviour of the intensity-potential profile of the bands for each excitation wavelength.

Effect of ESIPT-Induced Photoisomerization of Keto-Enamine Linkages on the Photocatalytic Hydrogen Evolution Performance of Covalent Organic Frameworks.

Photoexcitation of keto-enamine allows intramolecular proton transfer from C-NH to C=O, leading to tautomerization, while the photogenerated isomers are excluded from the study of photocatalytic applications. Herein, we demonstrate the photoisomerization of keto-enamine linkages on covalent organic frameworks (COFs) induced by excited-state intramolecular proton transfer (ESIPT). Partial enolization generates partially enolized photoisomers with a mixture of keto (C=O) and enol (OH) forms, conferring extended π-conjugation with an increase in electron density. The spatially separated D-A configuration is thus rebuilt with the enol-imine-linked branch as a donor and the keto-enamine-linked branch as an acceptor, and in turn, the photoinduced charges transfer between the two adjacent branches with a long lifetime. We further prove that the partially enolized photoisomer is a key transition instead of the keto-enamine form as an excited-state model to understand the photocatalytic behaviors. Therefore, ESIPT-induced photoisomerization must be considered for rationally designing keto-enamine-linked COFs with enhanced photocatalytic activity. Also, our study points toward the importance of controlling excited-state structures for long-lived separated charges, which is of particular interest for optoelectronic applications.

A coumarin-modified graphene quantum dot-based luminogen for the detection of cysteine in aqueous media.

A biocompatible fluorescence sensor for cysteine detection receives wide appreciation recently, because of its importance in the medical field. Functionalized graphene quantum dots (GQDs) are recently emerging biocompatible quantum dots, which are considered as suitable candidates for biomolecule detection. Motivated by this concept, here we have developed a versatile fluorescent probe based on 3-aminocoumarin (AMC) functionalized GQDs for the detection of cysteine (Cys). Modification on GQD with AMC resulted in a stable fluorescent probe with an enhancement in quantum yield of about 84% and 40 nm redshift in emission peak compared with bare GQD. The modified GQD is then used for the sensitive and selective detection of cysteine in aqueous media. The detection of Cys within the linear range of 50 nM to 1.5 μM was achieved with a detection limit (LOD) of 0.86 nM. Here, the AMC-GQD exhibit a turn-off fluorescence sensing behavior. The quenching mechanism was also explored. The sensing process follows dynamic quenching mechanism, which is attributed to the photoinduced charge transfer from AMC-GQD to Cys. The Stern-Volmer plot, energy-level alignment obtained from cyclic voltammetry measurements and density functional theory predictions give a valid proof for this. Furthermore, the sensor was applied efficiently to the determination of Cys in real water samples.

Managing photoinduced electronic interactions on a molybdenum disulfide/diblock copolymer/anionic porphyrin nanoensemble

Exploring the modular nature of MoS2 and its ability to be easily functionalized, both in covalent and non-covalent ways and with a variety of chemical species, a MoS2/diblock copolymer system was conceptualized. As the constituents of this diblock copolymer, the poly(benzyl methacrylate), abbreviated as pBzMA, block was designed to serve as the immobilization point of the polymeric chains onto the MoS2 lattice, taking advantage of the S-π non-covalent interactions between phenyl rings and ample S atoms, while the quaternized poly(dimethylamino-ethyl methacrylate), abbreviated as QpDMAEMA, was incorporated as the second block to capture the tetrasulfo-tetraphenyl anionic porphyrin, abbreviated as TPPS4 via electrostatic interactions with the ammonium groups of the quaternized polymeric chain. The so-formed MoS2/QpDMAEMA-b-pBzMA/TPPS4 ensemble was characterized and assessed via spectroscopic (UV-Vis), electron microscopy imaging (TEM) and dynamic light scattering (DLS) techniques. Markedly, efficient quenching of the characteristic fluorescence of the porphyrin species by the MoS2 nanosheets was observed, suggesting the development of photoinduced charge-transfer phenomena within the MoS2/QpDMAEMA-b-pBzMA/TPPS4 ensemble. This was further corroborated by time-correlated single photon counting (TCSPC) and blank experiments, signifying the role of Coulombic interactions for bringing into electronic communication the porphyrin moieties with MoS2. Overall, this rationally designed nanoensemble based on non-covalently modified MoS2 with polymers and photoactive species sets the foundations for inexpensive yet potent systems to be used in energy-related applications.

Photochemical decoration of gold nanoparticles on MoS2 nanoflowers grafted onto the flexible carbon cloth as a recyclable SERS sensor for the detection of antibiotic residues on curved surfaces

Surface-enhanced Raman spectroscopy (SERS)-based flexible substrate has recently been demonstrated to be effective in detecting molecules on curved surfaces, however a suitable method for fabricating the flexible SERS substrate still remains a hurdle. In this paper, we fabricated a flexible SERS substrate by anchoring the plasmonic gold nanoparticles (Au-NPs) onto the hydrothermally grown flower-like molybdenum disulfide (MoS2) grafted onto carbon cloth (CC) via a facile photoreduction route. Benefitting from the abundant hotspots generation of the Au-NPs and photo-induced charge-transfer ability of MoS2, the constructed Au-NPs/MoS2/CC substrate exhibit a superior SERS sensing ability, excellent SERS enhancement factor, high flexibility and mechanical stability towards the nitrofurantoin (NFT) with an ultra-low detection limit of 10−11 M. As a trial for practical applications, the flexible substrate was used to detect NFT (10−4 M) in the curved surfaces of meat samples via swab technique. The ability of the flexible Au-NPs/MoS2/CC substrate to sustain the robust Raman signals of NFT even after recycling up to 4 cycles validated its reusability. The proposed flexible SERS substrate with reusable capability indicates its great potential in practical applications for the detection of target molecules on the curved surfaces.

G-C3N4/PDI@ZnIn2S4 2D/2D organic–inorganic hybrid heterojunction with enhanced visible light photocatalytic property

In this study, we designed and fabricated novel g-C3N4/PDI@ZnIn2S4 2D/2D organic/inorganic hybrid heterojunctions consist of g-C3N4/PDI nanosheets and ZnIn2S4 nanosheets by a two-step-heating route followed by an oil-bath process for the first time. The synthesized heterojunctions were used as photocatalysts for the visible-light photodegradation of Rhodamine B (RhB), the composite photocatalysts displayed enhanced photocatalytic performance. Among them, the optimal photocatalyst exhibited significantly enhanced photocatalytic activity of up to 83.92 % after 120 min, which is nearly 7.0, 2.2, and 1.4 times higher than that of bare g-C3N4, g-C3N4/PDI, and ZnIn2S4, respectively. The enhanced photocatalytic activities can be attributed to the close interface contact and matched band structure between g-C3N4/PDI and ZnIn2S4, resulting in the formation of efficient heterojunctions, which accelerate the separation and transfer of photo-induced charges and improve the utilization of visible light. This work confirms the promising application prospects of g-C3N4/PDI@ZnIn2S4 photocatalysts in environmentalremediationfields.

Solvent-Induced Symmetry Breaking of the Photoinduced Charge Transfer Dynamics in the Bridged Perylene Dimer

Solvent-Induced Symmetry Breaking of the Photoinduced Charge Transfer Dynamics in the Bridged Perylene Dimer

Fluorescent Conversion Agent Embedded in Zinc Oxide as an Electron-Transporting Layer for High-Performance Non-Fullerene Organic Solar Cells with Improved Photostability.

Zinc oxide (ZnO) is widely used as an electron transporting layer (ETL) for organic solar cells (OSCs). Here, a low-cost commercial water/alcohol-soluble fluorescent conversion agent, sodium 2,2'-([1,1'-biphenyl]-4,4'-diyldivinylene)-bis(benzenesulfonate) (CBS), is incorporated into ZnO to develop a novel organic-inorganic hybrid ETL for high-performance OSCs. The photoinduced charge transfer from CBS to ZnO significantly improves the charge transport properties of ZnO, resulting in faster electron extraction and reduced charge recombination in OSC devices with ZnO:CBS ETLs. ZnO:CBS-based devices exhibit higher power conversion efficiencies (PCEs) than their pure ZnO-based counterparts, especially in devices with a thicker ETL, which is more suitable for roll-to-roll and large-area module processing. Furthermore, the strong ultraviolet-light absorption capability of CBS inhibits the photodegradation of the active layer, improving the photostability of ZnO:CBS based OSC devices. Therefore, this work provides a simple and effective strategy for realizing high-performance OSCs with high PCE and good photostability, which can further facilitate the commercialization of OSCs.

In situ construction of Ni-based N doped porous carbon induced by sulfurization or phosphorization for synergistically enhanced photo/electrocatalytic hydrogen evolution

Herein, two novel 3D porous Ni-based N doped carbon heterojunctions (NiS2@NC or Ni2P@NC) were successfully prepared through in situ carbonization and sulfurization or phosphorization by using flower-like Ni-based zeolite imidazolium framework as a precursor. Physiochemical and photoelectrochemical properties were investigated to explore photoinduced charge separation and transfer in the heterojunction. Meanwhile, the photo/electrocatalytic hydrogen evolution performances were evaluated systematically. In contrast to the controlled Ni-ZIF and Ni@NC composites, the expected flower-like NiS2@NC compounds show significantly enhanced photo/electrocatalytic hydrogen evolution performances, which is 13.8 times that of Ni-ZIF and 1.8 times that of Ni@NC. Furthermore, a phosphorus-decorated composite (Ni2P@NC) was synthesized for better comparison, which also displays apparently improved photo/electrocatalytic hydrogen evolution activities. The findings present that the synergistic effect of S doping and semiconducting NiS2 formation take responsibility for the enhancement of H2 generation over the NiS2@NC hybrids. This work can provide a new strategy to construct efficient ZIFs-based photo/electrocatalysts with high performance of H2 production.

Engineering multiple defect sites on ultrathin graphitic carbon nitride for efficiently photocatalytic conversion of lignin into monomeric aromatics via selective C–C bond scission

Lignin depolymerisation via photocatalytic cleavage of the selective interunit linkage in lignin could be a sustainable approach to produce monomeric aromatic chemicals. However, the insufficient investigation of interunit C–C bond fragmentation has obstructed the rational design of efficient photocatalytic system and further limit the yields of aromatic monomers from lignin depolymerisation. Herein, this work developed the ultrathin g-C3N4 with multiple defective sites by simple self-assembly process and in-situ thermal gas-shocking/etching process to catalyse the cleavage of lignin C–C bonds under visible light irradiation. Compared with the pristine g-C3N4, the developed g-C3N4 photocatalyst exhibited a superior catalytic activity (improved 102 %) and selectivity (∼90 %) in the cleavage of C–C bonds in lignin. This study demonstrated that the defects construction and ultrathin structure can optimise the electronic structures of g-C3N4 for better separation and transfer of photoinduced charges. And the control experiments and DFT calculation indicated that the created defect sites can promote the generation of essential reactive radicals (e.g., the activation of O2) and radical intermediates (C–H activation). The present work provides useful insights for the rational use of defect engineering in designing the efficient photocatalytic system for the conversion of lignin into aromatic monomers via the C–C bond cleavage.

Multistate Reaction Coordinate Model for Charge and Energy Transfer Dynamics in the Condensed Phase.

Constructing multistate model Hamiltonians from all-atom electronic structure calculations and molecular dynamics simulations is crucial for understanding charge and energy transfer dynamics in complex condensed phases. The most popular two-level system model is the spin-boson Hamiltonian, where the nuclear degrees of freedom are represented as shifted normal modes. Recently, we proposed the general multistate nontrivial extension of the spin-boson model, i.e., the multistate harmonic (MSH) model, which is constructed by extending the spatial dimensions of each nuclear mode so as to satisfy the all-atom reorganization energy restrictions for all pairs of electronic states. In this work, we propose the multistate reaction coordinate (MRC) model with a primary reaction coordinate and secondary bath modes as in the Caldeira-Leggett form but in extended spatial dimensions. The MRC model is proven to be equivalent to the MSH model and offers an intuitive physical picture of the nuclear-electronic feedback in nonadiabatic processes such as the inherent trajectory of the reaction coordinate. The reaction coordinate is represented in extended dimensions, carrying the entire reorganization energies and bilinearly coupled to the secondary bath modes. We demonstrate the MRC model construction for photoinduced charge transfer in an organic photovoltaic caroteniod-porphyrin-C60 molecular triad dissolved in tetrahydrofuran as well as excitation energy transfer in a photosynthetic light-harvesting Fenna-Matthews-Olson complex. The MRC model provides an effective and robust platform for investigating quantum dissipative dynamics in complex condensed-phase systems since it allows a consistent description of realistic spectral density, state-dependent system-bath couplings, and heterogeneous environments due to static disorder in reorganization energies.

Excited-State Proton Transfer in a Photoacid-Based Crystalline Coordination Compound: Reversible Photochromism, Near-Infrared Photothermal Conversion, and Conductivity.

By harnessing the power of coordination self-assembly, crystalline materials can act as carriers for photoacids. Unlike their solution-based counterparts, these photoacids are capable of altering the properties of the crystalline material under light and can even generate proton transfer in a solid-state environment. Due to the photoinduced proton transfer and charge transfer processes within this functional material, this crystal exhibits powerful absorption spanning the visible to near-infrared spectrum upon light irradiation. This feature enables reproducible, significant chromatic variation, near-infrared photothermal conversion, and photocontrollable conductivity for this photoresponsive material. The findings suggest that the synthesis of pyranine photoacid-based crystalline materials via coordination self-assembly can not only enhance light-harvesting efficiency but also enable excited-state proton transfer processes within solid crystalline materials, thereby maintaining and even improving the properties of photoacids.