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Strong metal–support interaction (SMSI) is a pivotal strategy in thermal catalysis; however, its application in photocatalysis leaves ample area for further development. A method inducing SMSI between earth-abundant metals, such as copper and TiO2, at room temperature, and thus hindering the agglomeration of copper species remains rarely reported. In this work, we achieved SMSI construction of TiO2 overlayers on Cu nanoparticles via a straightforward soft-chemistry method. SMSI coverage is stable even after high-temperature treatment in the air (500 °C), as demonstrated by chemical mapping and surface analysis. The method is more accurate than thermal reduction since it produces a metastable, highly active anatase phase. Interestingly, the TiO2 overlayer induces the formation of four-coordinated copper(II) species surrounded by oxygen atoms, resulting in coexisting CuO2 planes, which were monitored through high-resolution transmission electron microscopy and electron paramagnetic resonance spectroscopy. The stronger interfacial interaction by forming Ti–O–Cu bonding promotes charge carrier separation, producing twice as much H2 than the low interfacial interaction within a conventional photoactive system wherein copper was decorated onto TiO2. Our approach offers a rational design for SMSI materials in photocatalysis, which is extendable to other catalytic reactions. [ABSTRACT FROM AUTHOR]

Selective photocatalytic reduction of CO2 to value‐added fuels, such as CH4, is highly desirable due to its high mass‐energy density. Nevertheless, achieving selective CH4 with higher production yield on p‐block materials is hindered by non‐ideal adsorption of *CHO key intermediate and an unclear structure‐function relationship. Herein, we unlock the key reaction steps of CO2 and found a volcano‐type structure‐function relationship for photocatalytic CO2‐to‐CH4 conversion by gradual reduction of the p‐band center of the p‐block Bi element leading to formation of Bi‐oxygen vacancy heterosites. The selectivity of CH4 is also positive correlation with adsorption energy of *CHO. The Bi‐oxygen vacancy heterosites with an appropriate filled Bi‐6p orbital electrons and p band center (−0.64) enhance the coupling between C‐2p of *CHO and Bi‐6p orbitals, thereby resulting in high selectivity (95.2 %) and productivity (17.4 μmol g−1 h−1) towards CH4. Further studies indicate that the synergistic effect between Bi‐oxygen vacancy heterosites reduces Gibbs free energy for *CO‐*CHO process, activates the C−H and C=O bonds of *CHO, and facilitates the enrichment of photoexcited electrons at active sites for multielectron photocatalytic CO2‐to‐CH4 conversion. This work provides a new perspective on developing p‐block elements for selective photocatalytic CO2 conversion. [ABSTRACT FROM AUTHOR]

Imogolite nanotubes (INTs) are predicted as a unique 1D material with spatial separation of conduction and valence band edges but their large band gaps have inhibited their use as photocatalysts. The first step toward using these NTs in photocatalysis and exploiting the polarization‐promoted charge separation across their walls is to reduce their band gap. Here, the modification of double‐walled aluminogermanate INTs by incorporation of titanium into the NT walls is explored. The precursor ratio x = [Ti]/([Ge]+[Ti]) is modulated between 0 and 1. Structural and optical properties are determined at different scales and the photocatalytic performance is evaluated for H2 production. Although the incorporation of Ti atoms into the structure remains limited, the optimal condition is found around x = 0.4 for which the resulting NTs reveal a remarkable hydrogen production of ≈1500 µmol g−1 after 5 h for a noble metal‐free photocatalyst, a 65‐fold increase relative to a commercial TiO2‐P25. This is correlated to a lowering of the recombination rate of photogenerated charge carriers for the most active structures. These results confirm the theoretical predictions regarding the potential of modified INTs as photoactive nanoreactors and pave the way for investigating and exploiting their polarization properties for energy applications. [ABSTRACT FROM AUTHOR]

Integrating photonic crystals (PCs) into the design of a photocatalyst can significantly enhance its light‐harvesting capability. PCs can manipulate the propagation of light uniquely within a material and reduce its group velocity, thereby enhancing the absorption factor for photocatalysts. However, the slow photon effect in photoactive films with chiral nematic structures has not been reported yet, especially at the blue edge of the photonic bandgap. This work proposes a straightforward one‐pot method to fabricate various photonic films with chiral nematic, namely g‐C3N4/SiO2, TiO2/SiO2, and g‐C3N4/TiO2/SiO2. The sol‐gel biotemplating formulation using cellulose nanocrystals successfully leads to the elaboration of films exhibiting variable iridescent colors with photonic bandgap from UV to visible range. The tunable wavelength of the Bragg peak reflection offers the opportunity to access a region with a slow photonic effect, which directly impacts the light‐harvesting properties of the photoactive material. It is demonstrated that the H2 generation is significantly enhanced when the blue edge of the photonic bandgap position overlapped with the absorbance band of the photocatalyst. These results offer the opportunity to design photonic materials with chiral nematic structure and optimize the photocatalytic performance for energy application. [ABSTRACT FROM AUTHOR]

Although titanium dioxide (TiO2) has a wide range of potential applications, the photocatalytic performance of TiO2 is limited by both its limited photoresponse range and fast recombination of the photogenerated charge carriers. In this work, the preparation of nitrogen (N)-doped TiO2 accompanied by the introduction of oxygen vacancy (Vo) has been achieved via a facile annealing treatment with urea as the N source. During the annealing treatment, the presence of urea not only realizes the N-doping of TiO2 but also creates Vo in N-doped TiO2 (N-TiO2), which is also suitable for commercial TiO2 (P25). Unexpectedly, the annealing treatment-induced decrease in the specific surface area of N-TiO2 is inhibited by the N-doping and, thus, more active sites are maintained. Therefore, both the N-doping and formation of Vo as well as the increased active sites contribute to the excellent photocatalytic performance of N-TiO2 under visible light irradiation. Our work offers a facile strategy for the preparation of N-TiO2 with Vo via the annealing treatment with urea. [ABSTRACT FROM AUTHOR]

Metal halide perovskites (MHPs, CsPbX3: X = Cl, Br, I) have advanced the field of optoelectronic devices due to their remarkable light‐emitting capabilities, stemming from the large overlap between their emission and absorption spectra, offering the possibility to reabsorb their own emitted photons. Herein, a straightforward method is reported to confine CsPbBr3 into mesoporous silica films with a chiral nematic structure, allowing the amplification of the photoluminescence (PL). The simple room temperature ligand‐free synthesis allows facile growth of CsPbBr3 in silica photonic films, in which the Bragg peak position can be tuned from the UV to the visible range. The perovskite/silica films demonstrate a remarkable improvement in PL intensity and lifetime compared to the as‐synthesized non‐confined perovskite nanocrystals (NCs) due to the overlap of the Bragg peak position of the chiral nematic photonic films and CsPbBr3 absorption band. Such a PL enhancement stems from the slow photon effect induced at blue and red Bragg peak edges that facilitates the photon recycling of the emitted photons. This innovative approach offers a new way to fabricate highly emissive and long‐lived photoluminescent films at ambient conditions, potentially advancing perovskite utilization in light‐emitting devices. [ABSTRACT FROM AUTHOR]

Barium phosphate (Ba3(PO4)2) is a class of material that has attracted significant attention thanks to its chemical stability and versatility. However, the use of Ba3(PO4)2 as a photocatalyst is scarcely reported, and its use as a photocatalyst has yet to be reported. Herein, Ba3(PO4)2 nanoflakes synthesis is optimized using sol‐gel and hydrothermal methods. The as‐prepared Ba3(PO4)2 powders are investigated using physicochemical characterizations, including XRD, SEM, EDX, FTIR, DRS, J–t, LSV, Mott‐Schottky, and EIS. In addition, DFT calculations are performed to investigate the band structure. The oxidation capability of the photocatalysts is investigated depending on the synthesis method using rhodamine B (RhB) as a pollutant model. Both Ba3(PO4)2 samples prepared by the sol‐gel and hydrothermal methods display high RhB photodegradation of 79% and 68%, respectively. The Ba3(PO4)2 obtained using the sol‐gel process exhibits much higher stability under light excitation after four regeneration cycles. The photocatalytic oxidation mechanism is proposed based on the active species trapping experiments where O2•‒ is the most reactive species. The finding shows the promising potential of Ba3(PO4)2 photocatalysts and opens the door for further investigation and application in various photocatalytic applications. [ABSTRACT FROM AUTHOR]

Broken-gap heterojunctions are rarely used as photocatalysts due to their non-overlapping bandgap, which is a barrier to optimal charge carrier separation and higher photocatalytic efficiency. Based on our observations of higher charge carrier separation, light-harvesting ability, and good surface reaction, we show that a defect-rich broken-gap heterojunction can be used as an all-in-one photocatalyst. Depending on their localization (interface or surface), experimental characterization supported by DFT calculations evidence that defects facilitate photogenerated charge separation via efficient band-to-band quantum tunneling to form a type B heterojunction without adding bias voltage, boost the dissociation and activation of adsorbed water molecules, and induce a photothermal effect. The defect-rich broken-gap heterojunction WO3−x/ZnFe2O4−x grown on upconversion luminescent particles unexpectedly exhibited a remarkable H2 generation rate of 972.8 μmol g−1 h−1 for noble metals and cocatalyst-free photocatalysts. Such defect-rich broken-gap heterostructures offer an innovative solution, as they can function as an all-in-one heterojunction photocatalyst for solar-energy conversion. [ABSTRACT FROM AUTHOR]

Metal halide perovskites (MHPs, CsPbX3: X = Cl, Br, I) demonstrate high photogenerated charge-carrier production and mobility, which makes them promising candidates for photocatalysis. In this work, we investigated how adjusting the band gap energy of MHPs at room temperature by anion exchange (CsPbBr3−yXy: X = Cl, Br, I) leads to optimal interfacial electron transfer from CsPbBr3−yXy to TiO2 by means of transient absorption spectroscopy (TAS), time-resolved photoluminescence (TRPL), and time-resolved microwave conductivity (TRMC). We found that the formation of indirect excitons at the MHPs/TiO2 interface results in slower charge-carrier relaxation, which is essential for photocatalysis. The substitution of bromide with chloride reduces the trapping states (healing effect), which favors charge-carrier relaxation to the ground state and leads to higher charge recombination and lower photocatalytic activity. The iodine, on its side, acts as a hole trapper proposing an optimal band gap facilitating fast charge injection in the TiO2. The charge-carrier injection from one material to another suppresses recombination, leading to impressive H2 generation. [ABSTRACT FROM AUTHOR]

Material design is one of the major driving forces to enhance the intrinsic light harvesting ability of a photocatalyst. Herein, the design of black TiO2−x/CuxO with chiral‐like structures where Pt single atom (SA) is successfully deposited on both black TiO2−x and CuxO for visible‐light H2 generation is reported. Pt is well dispersed not only in the TiO2−x surface but also at the surface of CuxO, forming single‐atom alloys. Oxygen defects stabilize the Pt SAs deposition, which significantly enlarge the space charge layer, facilitating both the separation and transfer of photogenerated charge carriers. This structural optimization endows the black TiO2−x/CuxO/Pt film excellent light harvesting ability in the visible region, making it a promising visible‐light‐responsive photocatalyst. This work is expected to provide insights into the rational construction of nanostructured materials with chiral nematic structure exhibiting improved light harvesting ability. [ABSTRACT FROM AUTHOR]

Graphdiyne (GDY) with a direct bandgap, high charge carrier mobility, and ordered pore structure, is considered an excellent matrix for the construction of heterojunction photocatalysts. However, the traditional fabrication methods for GDY-based heterojunctions require a complicated deprotection of hexakis-[(trimethylsilyl)ethynyl]benzene (HEB-TMS) and usually result in localized heterojunctions. Herein, we developed a facile deprotection-free method to in situ grow GDY on the surface of C3N4 by directly using HEB-TMS as the precursor. Such a method enabled the formation of an integral GDY@C3N4 heterojunction, resulting in a significantly enhanced photocatalytic activity in the visible region. The optimized GDY@C3N4 showed 15.6-fold hydrogen production efficiency compared to pristine C3N4, and outperformed the GDY/C3N4 samples synthesized by other approaches (e.g. physical mixing, hydrothermal treatment and calcination treatment). This study provides a universal and efficient strategy for the design of GDY-based heterojunction photocatalysts for solar-to-hydrogen energy conversion. [ABSTRACT FROM AUTHOR]

Low selectivity is a key scientific challenge that hinders the commercialization of photocatalytic CO2 reduction. In their Research Article (e202407287), Zhao‐Qing Liu et al. found that the CH4 selectivity of p‐block Bi element exhibits a "volcanic" structure‐function relationship when gradually decreasing the p‐band center. This CH4 selectivity of Bi element is also positively correlated with the adsorption energy of key intermediate *CHO and the photoexcited carriers separation efficiency...By Jingwei Li; Tianci Xiang; Xiang Liu; Mohamed Nawfal Ghazzal and Zhao‐Qing LiuReported by Author; Author; Author; Author; Author [Extracted from the article]

Low selectivity is a key scientific challenge that hinders the commercialization of photocatalytic CO2 reduction. In their Research Article (e202407287), Zhao‐Qing Liu et al. found that the CH4 selectivity of p‐block Bi element exhibits a "volcanic" structure‐function relationship when gradually decreasing the p‐band center. This CH4 selectivity of Bi element is also positively correlated with the adsorption energy of key intermediate *CHO and the photoexcited carriers separation efficiency...By Jingwei Li; Tianci Xiang; Xiang Liu; Mohamed Nawfal Ghazzal and Zhao‐Qing LiuReported by Author; Author; Author; Author; Author [Extracted from the article]