Solar carbon dioxide (CO 2 ) conversion is an emerging solution to meet the challenges of sustainable energy systems and environmental/climate concerns. However, the construction of isolated active sites not only influences catalytic activity but also limits the understanding of the structure−catalyst relationship of CO 2 reduction. Herein, we develop a universal synthetic protocol to fabricate different single-atom metal sites (e.g., Fe, Co, Ni, Zn, Cu, Mn, and Ru) anchored on the triazine-based covalent organic framework (SAS/Tr-COF) backbone with the bridging structure of metal−nitrogen−chlorine for highperformance catalytic CO 2 reduction. Remarkably, the as-synthesized Fe SAS/Tr-COF as a representative catalyst achieved an impressive CO generation rate as high as 980.3 μmol g −1 h −1 and a selectivity of 96.4%, over approximately 26 times higher than that of the pristine Tr-COF under visible light irradiation. From X-ray absorption fine structure analysis and density functional theory calculations, the superior photocatalytic performance is attributed to the synergic effect of atomically dispersed metal sites and Tr-COF host, decreasing the reaction energy barriers for the formation of *COOH intermediates and promoting CO 2 adsorption and activation as well as CO desorption. This work not only affords rational design of state-of-the-art catalysts at the molecular level but also provides in-depth insights for efficient CO 2 conversion.

Developing robust oxygen evolution reaction (OER) catalysts requires significant advances in material design and in-depth understanding for water electrolysis. Herein, we report iridium clusters stabilized surface reconstructed oxyhydroxides on amorphous metal borides array, achieving an ultralow overpotential of 178 mV at 10 mA cm À2 for OER in alkaline medium. The coupling of iridium clusters induced the formation of high valence cobalt species and Ir-O-Co bridge between iridium and oxyhydroxides at the atomic scale,engineering lattice oxygen activation and non-concerted proton-electron transfer to trigger multiple active sites for intrinsic pH-dependent OER activity.T he lattice oxygen oxidation mechanism (LOM) was confirmed by in situ 18 O isotope labeling mass spectrometry and chemical recognition of negative peroxo-like species.Theoretical simulations reveal that the OER performance on this catalyst is intrinsically dominated by LOM pathway,facilitating the reaction kinetics. This work not only paves an avenue for the rational design of electrocatalysts,b ut also serves the fundamental insights into the lattice oxygen participation for promising OER application.

Direct photoelectrochemical (PEC) water splitting is a promising solution for solar energy conversion; however, there is a pressing bottleneck to address the intrinsic charge transport for the enhancement of PEC performance. Herein, a versatile coupling strategy was developed to engineer atomically dispersed Ni-N 4 sites coordinated with an axial direction oxygen atom (Ni-N 4 -O) incorporated between oxygen evolution cocatalyst (OEC) and semiconductor photoanode, boosting the photogenerated electron−hole separation and thus improving PEC activity. This state-ofthe-art OEC/Ni-N 4 -O/BiVO 4 photoanode exhibits a record high photocurrent density of 6.0 mA cm −2 at 1.23 V versus reversible hydrogen electrode (vs RHE), over approximately 3.97 times larger than that of BiVO 4 , achieving outstanding long-term photostability. From X-ray absorption fine structure analysis and density functional theory calculations, the enhanced PEC performance is attributed to the construction of single-atomic Ni-N 4 -O moiety in OEC/BiVO 4 , facilitating the holes transfer, decreasing the free energy barriers, and accelerating the reaction kinetics. This work enables us to develop an effective pathway to design and fabricate efficient and stable photoanodes for feasible PEC water splitting application.

The emergence of multi-drug-resistant pathogens threatens the healthcare systems world-wide. Recent advances in phototherapy (PT) approaches mediated by photo-antimicrobials (PAMs) provide new opportunities for the current serious antibiotic resistance. During the PT treatment, reactive oxygen species or heat produced by PAMs would react with the cell membrane, consequently leaking cytoplasm components and effectively eradicating different pathogens like bacteria, fungi, viruses, and even parasites. This Perspective will concentrate on the development of different organic photo-antimicrobials (OPAMs) and their application as practical therapeutic agents into therapy for local infections, wound dressings, and removal of biofilms from medical devices. We also discuss how to design highly efficient OPAMs by modifying the chemical structure or conjugating with a targeting component. Moreover, this Perspective provides a discussion of the general challenges and direction for OPAMs and what further needs to be done. It is hoped that through this overview, OPAMs can prosper and will be more widely used for microbial infections in the future, especially at a time when the global COVID-19 epidemic is getting more serious.

Direct photoelectrochemical (PEC) water splitting is of prime importance in sustainable energy conversion systems; however, it is a big challenge to simultaneously control light harvesting and charge transport for the improvement of PEC performance. Herein, we report a three-dimensional ordered macroporous (3DOM) CsTaWO6–x N x inverse opal array as a promising candidate for the first time. To address the critical challenge, an ultrathin carbon-nitride-based layer-intercalated 3DOM CsTaWO6–x N x architecture as a conformal heterojunction photoanode was assembled. This state-of-the-art conformal heterojunction photoanode with carrier-separation efficiency up to 88% achieves a high current density of 4.59 mA cm–2 at 1.6 V versus a reversible hydrogen electrode (vs RHE) under simulated AM 1.5G illumination, which is approximately 3.4 and 17 times larger than that of pristine CsTaWO6–x N x inverse opals and powers photoelectrodes in alkaline media, corresponding to an incident photon-to-current efficiency of 32% at 400 nm and outstanding stability for PEC water splitting. Density functional theory calculations propose that the intimate interface of a conformal photoanode optimizes the charge separation and transfer, thus enhancing the intrinsic water oxidation performance. This work enables us to elucidate the pivotal importance of 3DOM architectures and conformal heterostructures and the promising contributions to excellent PEC water-splitting applications.

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Solar energy conversion is one of the most versatile approaches for sustainable energy demands. The fundamental limitations for photocatalysis remain light absorption, charge separation, and photocatalytic (PC) performance of the catalysts. For the past few decades, defect engineering has been proven to be a promising solution for converting solar energy to chemical energy. In this regard, the recent progress of defect engineering toward solar energy conversion is summarized. Beginning with defects classification, the definition of various defects, synthesized strategies, and characterization techniques of controllable material defects are presented. The role of defect engineering on solar energy conversion is developed, extending light absorption, promoting charge separation, and facilitating stable PC reaction. The achievement of the defective photocatalysts is discussed toward versatile applications such as solar water splitting, CO2 reduction, nitrogen fixation, molecular activation, pollutants degradation, and solar cells. Finally, this Review, with regards to defect engineering, ends with the future opportunities and challenges for this exciting and emerging area for solar energy conversion.

A one-pot synthesis design on shape-controlled growth of Zn-based isoreticular metal−organic framework (i.e., IRMOF-3) was carried out in this work with the controllable crystal morphological evolution from simple cubes to several complex shapes. A new synthetic protocol was devised where poly(vinylpyrrolidone) (PVP), noble metal source (AgNO 3 ), mixed solvents (N,N-dimethylformamide (DMF)−ethanol mixture) and tetramethylammonium bromide (TMAB) were mutually introduced to the reaction medium as surfactant, adjuvant, accelerator, and structure-directing agent (SDA), respectively. Meanwhile, the crystallization process was investigated by a series of time-dependent experiments. Indeed, the added modulators and crystallization time were able to regulate the growth and thus the morphology of the final products. The resulting homogeneous IRMOF-3-Ag-n materials with unique and novel crystal morphologies were characterized via scanning electron microscopy (SEM), X-ray powder diffraction (XRD), thermogravimetric and differential thermal analyses (TG-DTA), transmission electron microscopy (TEM), infrared spectrum (IR), and optical microscope characterizations. Various shapes of IRMOF-3-Ag-n crystals as sorbents for capturing dibenzothiophene (DBT) were evaluated. Among all the morphology-controlled samples, IRMOF-3-Ag-5 with hollow sphere morphology was demonstrated to show the highest DBT capture capacity due to its unique morphology.