Rational Design Of Photocatalysts Research Articles

A binary dumbbell visible light driven photocatalyst for simultaneous hydrogen production with the selective oxidation of benzyl alcohol to benzaldehyde

Photocatalytic H2 production with selective oxidation of organic moieties in an aqueous medium is a fascinating research area. However, the rational design of photocatalysts and their photocatalytic performance are still inadequate. In this work, we efficiently synthesized the MoS2 tipped CdS nanowires (NWs) photocatalyst using soft templates via the two-step hydrothermal method for efficient H2 production with selective oxidation of benzyl alcohol (BO) under visible light illumination. The optimized MoS2 tipped CdS NWs (20 % MoS2) photocatalyst exhibits the highest photocatalytic H2 production efficiency of 13.55 mmol g−1 h−1 with 99 % selective oxidation of BO, which was 42.34 and 2.21 times greater photocatalytic performance than that of pristine CdS NWs and MoS2/CdS NWs, respectively. The directional loading of MoS2 at the tips of CdS NWs (as compared to nondirectional MoS2 at CdS NWs) is the key factor towards superior H2 production with 99 % selective oxidation of BO and has an inhibitory effect on the photo corrosion of pristine CdS NWs. Therefore, the amazing enhancement in the photocatalytic performance and selectivity of optimized MoS2 tipped CdS NWs (20 % MoS2) photocatalyst is due to the spatial separation of their photoexcited charge carriers through the Schottky junction. Moreover, the unique structure of the MoS2 flower at the tip of 1D CdS NWs offers separate active sites for adsorption and surface reactions such as H2 production at the MoS2 flower (confirmed by Pt photo deposition) and subsequently the selective oxidation of BO at the stem of CdS NWs. This rational design of a photocatalyst could be an inspiring work for the further development of an efficient photocatalytic system for H2 production with selective oxidation of BO (a strategy of mashing two potatoes with one fork).

Surface-engineering of CaTiO3 for photocatalytic hydrogen evolution reaction through enhanced oxygen vacancy

Surface engineering has been an important strategy in attaining a higher catalytic activity in comparison with pristine samples. CaTiO3 is a well-known photoactive material but lacks photo-to-electron conversion efficiency. Herein, we demonstrate a simple path-way that could achieve a higher surface area, active site exposure, and oxygen vacancies. The experimental results using different concentrations of HNO3 illustrated the selective leaching of Ca(II) ions, which leads to the partial conversion of Ti4+ to Ti3+ and the formation of oxygen vacancy. This eventually resulted in an engineered electronic state that modifies the band alignment and improves the charge transfer and migration rate. The optimized photocatalyst (CTO-5) exhibits approximately six times enhanced hydrogen evolution rate of 58.1 μmol∙g−1 h−1 than the pristine CaTiO3 (8.7 μmol∙g−1 h−1). Our work offers new intuitions into the rational design of photocatalysts with surface-engineering methodology without using any noble metal.

Complete Photooxidation of Formaldehyde to CO2 via Ni-Dual-Atom Decorated Crystalline Triazine Frameworks: A DFT Study.

Formaldehyde (CH2O) emerges as a significant air pollutant, necessitating effective strategies for its oxidation to mitigate adverse impacts on human health and the environment. Among various technologies, the photooxidation of CH2O stands out owing to its affordability, safety, and effectiveness. Nitrogen-rich crystalline triazine-based organic frameworks (CTFs) exhibit considerable potential in this domain. Nevertheless, the weak and unstable CH2O adsorption hinders the overall oxidation efficiency of CTF. To address this limitation, we incorporate single and dual Ni atoms into nitrogen-rich CTFs by density functional theory (DFT) calculations, resulting in CTF-Ni and CTF-2Ni. This strategic modification significantly enhances the adsorption capability of CH2O. Notably, this synergy between Ni dual atoms activates CH2O by strong chemical adsorption, thereby reducing the energy barrier of CH2O oxidation and achieving the complete oxidation of CH2O to CO2. Moreover, the introduction of dual-atom Ni over CTF ameliorates visible and near-infrared light absorption and facilitates photoexcited charge transfer and separation. Finally, the underlying mechanisms of complete CH2O oxidation over CTF-2Ni are proposed. This work offers novel insights into the rational design of photocatalysts for CH2O oxidation through the integration of Ni dual atoms into CTFs.

Glucose photorefinery for sustainable hydrogen and value-added chemicals coproduction

As a naturally occurring and stable energy supply, biomass will be the leading renewable energy in the future, and its high-value application will help promote the realization of carbon neutrality. Glucose, as the basic unit of lignocellulosic biomass, has been widely investigated as the feedstock to produce various value-added chemicals. Compared to the traditional glucose valorization platforms, such as thermal catalysis and biological fermentation, solar-driven photocatalysis holds the advantages in mild reaction conditions and controllable reaction kinetics, and it is emerging as a sustainable and efficient technology for glucose conversion. With the rational design of the photocatalysts, glucose could be selectively converted into specified chemicals via oriented bond cleavage along with the sustainable generation of hydrogen at the same time, which is the so-called glucose photorefinery process. This present review introduces the general principles and latest progress in glucose photorefinery. The rational design of bifunctional photocatalysts to achieve extended light absorption, efficient charge separation, and favorable surface reaction is also introduced. The oriented breakage of the chemical bonds in glucose molecules to produce different chemicals on different active sites is highlighted. Finally, challenges and perspectives on glucose photorefinery to achieve further efficiency and more fruitful reaction pathways are proposed. This present review is believed to provide guidance for the biomass valorization by mild photocatalysis to simultaneously produce sustainable fuels and chemicals with the rational design of dually functional photocatalysts.

Interfacial modulation of α-Ag1.82Cu0.09WO4 with high active BiOClxI1−x for boosting photocatalytic activity and degradation of emerging contaminants under direct sunlight

Removal of organic contaminants in wastewater using sunlight-driven photocatalysts has received significant attention in recent years. However, the rational design of photocatalysts to attain high light absorption, lower charge carrier recombination with efficient photocatalytic activity and good recycling capability is crucial for the practical photocatalysis process. Herein, solid-state Z-scheme BiOCl0.6I0.4/α-Ag1.82Cu0.09WO4 heterojunction is synthesized by assembling hierarchical 3D-BiOCl0.6I0.4 nanoflowers on cube-like 3D-α-Ag1.82Cu0.09WO4 surface through a hydrothermal method. A wide range of characterization techniques confirms the successful synthesis of BiOClxI1−x (0 ≤ x ≤ 1.0), α-Ag1.82Cu0.09WO4 and BiOCl0.6I0.4/α-Ag1.82Cu0.09WO4 binary composites. The TC antibiotic removal efficiency of 30 wt% BiOCl0.6I0.4/α-Ag1.82Cu0.09WO4 binary composite reaches 95.91% within 120 min under natural sunlight irradiation and the rate constant is 1.81 and 3.33 times higher than the pristine BiOCl0.6I0.4 and α-Ag1.82Cu0.09WO4, respectively. The optimized binary heterojunction exhibits excellent photocatalytic performance for toxic pollutants like MB (η = 97.27%) and RhB (η = 95.75%) under direct sunlight irradiation. The favorable photocatalytic activity of binary heterojunction is ascribed to enhancing the sunlight absorption range, the tight contact interface and the effective separation of electron/hole pairs. Notably, 30 wt% BiOCl0.6I0.4/α-Ag1.82Cu0.09WO4 binary composite exhibits attractive recycling ability and good photostability for prolonged sunlight irradiation. Furthermore, the total organic carbon results also confirm that the 30 wt% BiOCl0.6I0.4/α-Ag1.82Cu0.09WO4 efficiently mineralized the model pollutants (TC antibiotic, MB and RhB) into other unharmful compounds under sunlight irradiation. In summary, this work offers an effective strategy to prepare solid-state Z-scheme heterojunction with favorable photocatalytic activity, which can increase wastewater purification efficiency.

Porphyrin sensitized ZnWO4 nanosheets with CuO nanoparticles for photocatalytic hydrogen evolution

Photocatalytic hydrogen production is a promising technique for solar-to-chemical energy conversion. However, the efficiency of this method is greatly limited by the need to develop efficient photocatalysts. In this study, we rationally designed an organic–inorganic hybrid material as a photocatalyst for hydrogen production. ZnWO4 nanosheets were fabricated via a hydrothermal reaction, before decorating with CuO nanoparticles as a co-catalyst for hydrogen evolution and tetrakis(4-carboxyphenyl) porphyrin (TCPP) as a photosensitizer. The as-fabricated ZnWO4/CuO/TCPP obtained excellent photocatalytic hydrogen evolution (1.84 mmol g−1 h−1) under the optimized reaction conditions, which was about 4.9 times higher compared with that using the pristine ZnWO4. This significant enhancement was ascribed to the efficient charge separation by CuO and light absorption extension by porphyrin. Thus, we demonstrated a good example of efficient hydrogen production based on the rational design of photocatalysts.

Bandgap engineering control bifunctional MnxCd1-xS photocatalysts selectively reforming xylose to C3 organic acids and efficient hydrogen production

The simultaneous reforming of biomass into high value-added chemicals and H2 production by water splitting in a green and environmentally clean way is a very challenging task. Herein, we demonstrate the design of bifunctional MnxCd1-xS photocatalyst with a controllable band gap by bandgap engineering. Bandgap engineering effectively regulates the oxidation and reduction capacity of materials. The design of photocatalysts with suitable conduction bands and valence bands makes the targeted conversion of xylose possible. Innovative conversion of xylose to glyceric acid, lactic acid, and propanoic acid. The optimized Mn0.7Cd0.3S catalyst showed excellent performance in the production of H2 (14.06 mmol·gcat-1·h−1, 29.9 times more than CdS and 351.5 times more than MnS), xylose conversion (90%), and C3 organic acid yield (59.2%) without cocatalyst and any scavengers under visible light irradiation. This work shows that a rational photocatalyst design can achieve efficient simultaneous production of high value-added chemicals and clean energy.

Self-sacrificed BiOBr template-assisted synthesis of α-Bi2O3/Bi3O4Br heterojunctions with oxygen vacancies for enhanced photocatalytic nitrogen fixation

The catalytic conversion of nitrogen to ammonia is one of the most significant processes in nature and the chemical industry. However, the traditional Haber-Bosch process of ammonia synthesis consumes substantial energy and emits a large amount of carbon dioxide. The efficiency of photocatalytic N2 activation is severely limited by the lack of N2 adsorption sites and poor carrier utilization. Herein, an efficient α-Bi2O3/Bi3O4Br heterojunction is proposed with a photocatalytic nitrogen fixation activity of 238.67 μmol·g−1·h−1. Compared with the BiOBr precursor, α-Bi2O3 and Bi3O4Br, the α-Bi2O3/Bi3O4Br heterojunction with oxygen vacancies can improve the adsorption and activation capacity of N2 and promote the separation efficiency of charge carrier pairs by accommodating photogenerated electrons under visible light through the mechanism of N-type semiconductors. Therefore, oxygen vacancies and heterojunction engineering of semiconductive nanomaterials provide a promising method for the rational design of photocatalysts to enhance the rate of ammonia synthesis under mild conditions.

(Invited) Tuning Photocatalytic Activity with Energetic and Kinetic Asymmetry at Coating-Stabilized Particulate Semiconductors

Semiconductor photocatalysts coevolve reductive and oxidative reactions at nanoscale proximity. The local charge separation and local coevolution have unique advantages: i) photocatalysts can operate in neutral pH water or water vapor instead of strong acid or base; ii) most semiconductors form a self-passivating layer at corroded surfaces to prevent corrosion propagation; and iii) nanoparticulate photoabsorbers or nanocrystalline films have achieved near-unity quantum efficiency, promising scale-up solar-to-chemical conversion. Despite the near-unity quantum efficiency achieved for SrTiO3 particles, the Edisonian approach is applied to the vast majority of photocatalysts, thus limiting progress. Technologically important semiconductors of 1.1 – 2.3 eV bandgaps and properly adjusted band edges, such as GaP and Si, can be ball milled into powder, followed by chemical passivation and protective coating processes. Thus, we introduce the Hu-lab-invented charge-transport coatings to protect semiconductors, such as silicon and gallium indium phosphide. We tune their photocatalytic activity by varying and measuring the energetics and kinetics at local reactive sites, in the following case studies.First, we combine photoelectrochemical cells with local potential-sensing probe microscopy to elucidate photocatalytic processes. In particular, we focus on local energetics and kinetics of multiple concurrent redox processes, i.e., two-redox chemistry. Figure 1A illustrates such a three-terminal photo-electro-catalytic cell setup, where the photoelectrode materials are photocatalysts by themselves. We showcase the efficient charge-separation design by fabricating photocatalysts with particulate semiconductors (e.g., commercial CdS powders, GaInP2 epitaxial layers, and ball-milled GaP nanoparticles), TiO2 coatings, and Rh cocatalysts for the concurring reduction of water and oxidation of reversible redox mediators or sacrificial reagents.We discovered that nanoscale site energetics are mutually dependent on local charge-transfer kinetics.[1] Besides, all known visible-light active photocatalysts of 1.1 – 2.3 eV bandgap photo-oxidize or corrode in water.[2] We discovered multi-functional protective coatings that i) allow for both electrons and holes to transport at tunable energy levels;[3] ii) shift band edges favorably, [4]; iii) reduce charge trapping and recombination,[5] and iv) tune water-oxidation selectivity between O2 and hydrogen peroxide production. [6] We show that in the presence of quinone redox couples in a bicarbonate solution, CO is produced with a 1-atm CO2-free Ar-purged headspace where the only source of CO2 is the (bi)carbonate anions, whilst the quinone redox couples can systematically vary the band edge positions of GaInP photoabsorbers.As shown in Figure 1B, CO evolution rate for both Fe(CN)6 3-/4- and H2BQ/BQ are higher at pH 7 than pH 8.5. The local CO2 concentration at pH 8.5 limited CO production rates. This observation corroborates our hypothesis that photocatalytic redox reactions locally drive pH swing to release CO2 at the oxidative sites, whereas the nearby reductive sites reduce in-situ generated CO2 into CO2R products. We envision direct solar fuel production from natural resources such as sunlight, bicarbonates from the ocean, or moisture in the air in a durable particle reactor.[7] We also processed wood and leaves into pulps and performed photocatalytic H2 production from the CdS/TiO2/Rh/CoOx panel (Figure 1C) using bottom LED illumination, as the glucose solution became colored.In summary, we show the rational design of photocatalysts. These coating-stabilized semiconductor particles present a scalable pathway for making H2 while effectively activating water and biomass as the two most abundant oxidants. We address the timescale mismatch between light absorption and catalysis by effectively accumulating electrons and holes at the respective reductive and oxidative sites.[8] The study paves the way for utilizing biomass to obtain bioenergy with carbon capture and storage.

Achieving High Selectivity in Photocatalytic Oxidation of Toluene on Amorphous BiOCl Nanosheets Coupled with TiO2.

The inert C(sp3)-H bond and easy overoxidation of toluene make the selective oxidation of toluene to benzaldehyde a great challenge. Herein, we present that a photocatalyst, constructed with a small amount (1 mol %) of amorphous BiOCl nanosheets assembled on TiO2 (denoted as 0.01BOC/TiO2), shows excellent performance in toluene oxidation to benzaldehyde, with 85% selectivity at 10% conversion, and the benzaldehyde formation rate is up to 1.7 mmol g-1 h-1, which is 5.6 and 3.7 times that of bare TiO2 and BOC, respectively. In addition to the charge separation function of the BOC/TiO2 heterojunction, we found that the amorphous structure of BOC endows its abundant surface oxygen vacancies (Ov), which can further promote the charge separation. Most importantly, the surface Ov of amorphous BOC can efficiently adsorb and activate O2, and amorphous BOC makes the product, benzaldehyde, easily desorb from the catalyst surface, which alleviates the further oxidation of benzaldehyde, and results in the high selectivity. This work highlights the importance of the microstructure based on heterojunctions, which is conducive to the rational design of photocatalysts with high performance in organic synthesis.

Prediction of Redox Power for Photocatalysts: Synergistic Combination of DFT and Machine Learning.

The accurate prediction of excited state properties is a key element of rational photocatalyst design. This involves the prediction of ground and excited state redox potentials, for which an accurate description of electronic structures is needed. Even with highly sophisticated computational approaches, however, a number of difficulties arise from the complexity of excited state redox potentials, as they require the calculation of the corresponding ground state redox potentials and the estimation of the 0-0 transition energies (E0,0). In this study, we have systematically evaluated the performance of DFT methods for these quantities on a set of 37 organic photocatalysts representing 9 different chromophore scaffolds. We have found that the ground state redox potentials can be predicted with reasonable accuracy that can be further improved by rationally minimizing the systematic underestimations. The challenging part is to obtain E0,0, as calculating it directly is highly demanding and its accuracy depends strongly on the DFT functional employed. We have found that approximating E0,0 with appropriately scaled vertical absorption energies offers the best compromise between accuracy and computational effort. An even more accurate and cost-effective approach, however, is to predict E0,0 with machine learning and avoid the use of DFT for excited state calculations. Indeed, the best excited state redox potential predictions are achieved with the combination of M062X for ground state redox potentials and machine learning (ML) for E0,0. With this protocol, the excited state redox potential windows of the photocatalyst frameworks could be adequately predicted. This shows the potential of combining DFT with ML in the computational design of photocatalysts with preferred photochemical properties.

New insight into efficient photocatalytic CO2 reduction without any sacrifice agent over the novel hierarchical structured SiOC whisker aerogel

Photoreduction of CO2 to valuable fuels provides a promising strategy for managing the global carbon balance using renewable solar energy, yet the design of active, cost-effective, highly selective, and stable CO2 reduction photocatalysts remains a big challenge. Herein, we report a novel SiOC aerogel photocatalyst synthesized by a simple one-step sol-gel process, combined with the supercritical drying technique and heat treatment processes. The resulting SiOC aerogel exhibits a large BET specific area with typical hierarchical structures, which is responsible for the enhanced photocatalytic activity. In addition, the formation mechanism of the SiOC whisker aerogel is revealed in this study. The optimized SiOC aerogel exhibits CH4 and CO evolution activity of 5.8 and 20.5 μmol/g under simulated sunlight irradiation, respectively, without any additional co-catalyst or sacrificial agent, which is 6.4 and 3.9 times higher than those of the pristine SiC aerogel. The density functional theory (DFT) calculation confirms that the resulting SiOC aerogel can effectively adsorb and activate CO2 and H2O molecules on the catalyst surface. The Gibbs free energy diagram further verifies the superior performance of the resulting SiOC aerogel over the pristine SiC and SiO2 cluster via the rate-determining step calculations. The high efficiency of CO2 reduction can be attributed to the structural merits and the electronic structures modulation, which greatly achieves fast separation and transfer of charge carriers. The work paves an insight into the rational design of photocatalysts toward simultaneously facilitating carrier separation and CO2 activation from aerogel-based porous materials.

Revealing the Importance of Hole Transfer: Boosting Photocatalytic Hydrogen Evolution by Delicate Modulation of Photogenerated Holes

Photocatalytic hydrogen evolution (PHE) has gained massive attention for the development of renewable resources. Currently, prominent and stable PHE is still restricted by the limited utilization of photocatalytic charge carriers, especially holes, of which the transfer rate is approximately two to three orders of magnitude slower than that of electrons. Although it is widely accepted that surface holes can be consumed by electron donors, the rational design of photocatalysts to speed up hole transfer and understand the ultrafast photodynamics as well as the exploration of the effect of oxidation products is still highly urgent. Herein, cadmium sulfide (CdS), as the model photocatalyst, is investigated for prominent PHE based on hole modulation strategies. To accelerate the surface reaction, H2S-saturated Na2S&Na2SO3 solution, which outperforms traditional hole scavengers, is selected to remove the holes accumulating on the photocatalyst surface, while the oxidative cocatalyst palladium sulfide (PdS) is simultaneously impregnated on CdS to optimize the hole transfer process. Evidenced by femtosecond transient absorption spectroscopy (TAS) and band structure analysis, the ultrafast process (1–5 ps) highly related with hole transfer from CdS to PdS is proved in the CdS/PdS composite. More importantly, density functional theory (DFT) calculation suggests that the hole accumulation site (PdS) is also the oxidation active site where the active species (HS*) adsorbs on. Finally, the oxidation product composition is analyzed through Fourier transform infrared (FTIR) spectroscopy, which indicates that the colorless and value-added product S2O32– protects the photocatalyst from the light shielding effect. Contributed by factors mentioned above, improved PHE efficiency (∼145.9 mmol·g–1·h–1) is achieved on the CdS/PdS composite.

Effects of surface fluoride modification on TiO2 for the photocatalytic oxidation of toluene

In the present study, we investigated the influence of surface fluorine (F) on TiO2 for the photocatalytic oxidation (PCO) of toluene. TiO2 modified with different F content was prepared and tested. It was found that with the increasing of F content, the toluene conversion rate first increased and then decreased. However, CO2 mineralization efficiency showed the opposite trend. Based on the characterizations, we revealed that F substitutes the surface hydroxyl of TiO2 to form the structure of Ti-F. The presence of the appropriate amount of surface Ti-F on TiO2 greatly enhanced the separation of photogenerated carriers, which facilitated the generation of ·OH and promoted the activity for the PCO of toluene. It was further revealed that the increase of only ·OH promoted the conversion of toluene to ring-containing intermediates, causing the accumulation of intermediates and then conversely inhibited the ·OH generation, which led to the decrease of the CO2 mineralization efficiency. The above results could provide guidance for the rational design of photocatalysts for toluene oxidation.

Biomass Photoreforming for Hydrogen and Value‐Added Chemicals Co‐Production on Hierarchically Porous Photocatalysts

AbstractBiomass, a naturally abundant, sustainable and clean resource has great potential as an alternative to replace the limited fossil feedstock for value‐added chemicals and fuels. Biomass with abundant reductive functional groups could theoretically act as electron donor to consume photogenerated holes and/or active free radicals. Biomass photoreforming over semiconductor photocatalysts using solar light as energy input attracts much attention in this context. However, biomass photoreforming still suffers low conversion efficiency and product selectivity due to its structural complexity, poor solubility and unclear reaction mechanism. Owing to the advanced features of mass diffusion of biomass derivatives and adjustable surface properties, hierarchically porous photocatalysts with desired active sites at each length scale of porosity have shown their superiority in boosting the conversion efficiency and selectivity of biomass photoreforming. Herein, a critical review is presented on selective biomass photoreforming for simultaneous H2 and value‐added chemicals co‐production on hierarchically porous photocatalysts. The fundamentals of biomass photoreforming and current bottleneck of biomass valorization by photocatalytic process are presented and analyzed. The rational photocatalyst design with hierarchically porous structure to improve the biomass conversion and product selectivity by boosting mass transfer is highlighted. Finally the challenges and opportunities for photocatalytic biomass valorization are presented in the perspective ssection.

Operando Laboratory X-ray Absorption Spectroscopy and UV–Vis Study of Pt/TiO2 Photocatalysts during Photodeposition and Hydrogen Evolution Reactions

Photocatalytic hydrogen (H2) production is a promising route for alternative energetics. Understanding structure–activity relationships is a crucial step towards the rational design of photocatalysts, which requires the application of operando spectroscopy under relevant working conditions. We performed an operando investigation on a catalytic system during the photodeposition of Pt on TiO2 and photostimulated H2 production, using simultaneous laboratory X-ray absorption spectroscopy (XAS), UV–Vis spectroscopy, and mass spectrometry. XAS showed a progressive increase in Pt fluorescence for Pt deposited on TiO2 for over an hour, which is correlated with the signal of the produced H2. The final Pt/TiO2 catalyst contained Pt(0) particles. The electronic features corresponding to the Pt4+ species in the UV–Vis spectrum of the solution disappear as soon as UV radiation is applied in the presence of formic acid, which acts as a hole scavenger, resulting in the presence of Pt(0) particles in solution.

Self-assembly synthesis of hollow phosphorus-doped graphitic carbon nitride microboxes for the photodegradation of organic pollutants.

The rational design of photocatalysts with efficiency and stability is highly desirable but remains challenging. Here, we report a supramolecular self-assembly strategy to construct hollow phosphorus-doped g-C3N4 microboxes (PCNMs). Considering the effects of multiple parameters on the structure and activity of samples, the orthogonal design is innovatively introduced to optimize technology parameters for screening high-performance g-C3N4. Under visible light irradiation (λ ≥ 420 nm), rhodamine B (RhB, 4 mg L-1) is completely degraded in just 80 seconds in the presence of the optimal PCNM. The kinetic rate constant of RhB degradation with the PCNM is 3.4633 min-1, demonstrating unprecedented activity that is about 112 times higher than that of bulk g-C3N4 (0.0309 min-1) synthesized by direct polycondensation of melamine. Additionally, the optimal PCNM also shows enhanced degradation efficiency for tetracycline. The outstanding properties are primarily attributed to the hollow architecture, high specific surface area, and phosphorus doping. This work advances the design of photocatalysts correlating various factors, opening an avenue for optimizing photocatalytic synthesis and activity.

Quantitative prediction of excited-state decay rates for radical anion photocatalysts.

We present a computational approach for predicting key properties of organic radical anions, including excited-state lifetimes and redox potentials. The approach shows good agreement with experimental data and has potential for in silico screening to facilitate the rational design of photocatalysts.

Metallic Bi and oxygen vacancy dual active sites enable efficient oxygen activation: Facet-dependent effect and interfacial synergy

Surface atomic arrangement and coordination of different crystal facets significantly affect the catalytic reactivity of photocatalysts. By modulating the solvent environment, we developed a one-step solvothermal route to synthesize a series of BiOBr nanosheets with different dominating facets ((001) and (010)) and simultaneously decorated metallic Bi and oxygen vacancies (OVs) on the identified preferred facets ((010)). The resulting Bi/OV-BiOBr-(010) outperform BiOBr-(010) with mono OVs, bare BiOBr-(010), and other well-known photocatalysts in both O2 activation and pollutant degradation under both same catalyst loading and optical thickness conditions. The synergistic effects of the Bi-OV dual active sites in O2 adsorption-activation and charge separation-transfer were confirmed by experimental characterization and DFT calculation. This study highlights the facet-dependent synergy of plasmonic metal-defect dual active sites and shed light on the rational design of photocatalysts for more efficient O2 activation and refractory pollutant degradation.

Heterojunction within dual electric fields dynamically tailoring charge transfer to surface redox active sites for efficient H2 generation

Flying broom-like heterojunction photocatalysts with internal electric field synergizing polarized field has been constructed by spontaneously assembling CuO nanoparticles on polarized g-C3N4 microfibers (p-C3N4Fs) with using a facile hydrothermal method. Theoretical prediction and characterizations confirm that, photo-generated electrons and holes are dynamically transferred to reductive sites of pyridine-like N in p-C3N4Fs and oxidative sites of Cu atom in CuO for H2O splitting within the dual electric fields, respectively. Stoichiometric H2 and O2 evolution with solar energy conversion into H2 energy of 1.22 % has been achieved under AM 1.5G irradiation in photocatalytic H2O overall splitting by heterojunction photocatalytic mechanism of translation, rotation, transformation of protons and intermediates. The rational photocatalyst design on heterojunction with dual electric fields breaks the long-term thought of regulating charge carriers only by internal electric field, which will provide a unique perspective to deepen the kinetic study on the spatial separation and directional migration of photogenerated charges to the surface redox active sites for solar energy conversion.