Facilitating Oriented Electron Transfer from Cu to MoC MXene for Weakened Mo─H Bond Toward Enhanced Photocatalytic H Generation.

MoC MXene (MoCT) is recognized as an excellent cocatalyst due to unique physicochemical properties and platinum-like d-band of Mo active sites. However, Mo sites of MoCT with high-density empty d-orbitals exhibit strong Mo─H bonds during photocatalytic hydrogen evolution, leading to easy adsorption of hydrogen ions from solution and unfavorable desorption of H from Mo sites. To weaken the Mo─H bond, a strategy of oriented electron transfer from Cu to MoCT to increase the antibonding orbital occupancy of Mo─H hybrid orbitals is implemented by introducing Cu into MoCT interlayers to form Cu-MoCT.

Platinum-induced nanolization and electron-deficient gold in platinum@gold cocatalyst for efficient photocatalytic hydrogen peroxide production.

Simultaneous optimization of the number and intensity of oxygen (O) adsorption on gold (Au) cocatalyst is highly required to greatly improve their interfacial hydrogen peroxide (HO)-production activity. However, it is a great challenge to realize the above effective modulation of Au by traditional photodeposition route. In this study, a platinum (Pt)-induced selective photodeposition method was designed to simultaneously regulate the particle size and electronic structure of Au cocatalyst for boosting the photocatalytic HO-production activity of bismuth vanadate (BiVO) via the selective deposition of Pt@Au core-shell cocatalyst.

Releasing Au Electrons to Mo Site for Weakened Mo─H Bond of MoC MXene Cocatalyst Toward Improved Photocatalytic H Production.

MoC MXene (MoCT) is one of the most promising noble-metal-free cocatalysts for photocatalytic H production because of its excellent electron transport capacity and abundant Mo sites. However, MoCT typically exhibits a strong Mo─H bond, resulting in that the produced H difficultly desorbs from the Mo surface for the limited activity. To effectively weaken the Mo─H bond, in this paper, a regulation strategy of electron donor Au releasing electrons to the d-orbitals of Mo sites in MoCT is proposed.

Synchronous optimization of HO and H adsorption on NiOTe nanodots for alkaline photocatalytic H evolution.

Suitable HO and H adsorption on the surface of transition metal chalcogenide cocatalyst is highly required to achieve their excellent alkaline H-evolution rate. However, the weak adsorption of HO and H atoms on NiTe surface greatly hinders its alkaline H-evolution efficiency. Herein, an electron-deficient modulation strategy is proposed to synchronously improve the adsorption of HO and H atoms on NiTe surface, which can greatly improve the alkaline photocatalytic H evolution of TiO.

Charge self-regulation over in-plane two-dimensional/two-dimensional hetero-cocatalyst for robust photocatalytic hydrogen generation.

The rationally designing and constructing atomic-level heterointerface of two-dimensional (2D) chalcogenides is highly desirable to overcome the sluggish HO-activation process toward efficient solar-driven hydrogen evolution. Herein, a novel in-plane 2D/2D molybdenum disulfide-rhenium disulfide (ReS-MoS) heterostructure is well-designed to induce the charge self-regulation of active site by forming electron-enriched Re and electron-deficient S sites, thus collectively facilitating the activation of adsorbed HO molecules and its subsequent H evolution. Furthermore, the obtained in-plane heterogenous ReS-MoS nanosheet can powerfully transfer photoexcited electrons to inhibit photocarrier recombination as observed by advanced Kelvin probe measurement (KPFM), in-situ X-ray photoelectron spectroscopy (XPS) and femtosecond transient absorption spectroscopy (fs-TAS).

Enhancing photocatalytic HO production with Au co-catalysts through electronic structure modification.

Gold-based co-catalysts are a promising class of materials with potential applications in photocatalytic HO production. However, current approaches with Au co-catalysts show limited HO production due to intrinsically weak O adsorption at the Au site. We report an approach to strengthen O adsorption at Au sites, and to improve HO production, through the formation of electron-deficient Au sites by modifying the electronic structure.

Free-Electron Inversive Modulation to Charge Antibonding Orbital of ReS Cocatalyst for Efficient Photocatalytic Hydrogen Generation.

The free electron transfer between cocatalyst and photocatalyst has a great effect on the bonding strength between the active site and adsorbed hydrogen atom (H), but there is still a lack of effective means to purposely manipulate the electron transfer in a beneficial direction of H adsorption/desorption activity. Herein, when ReS cocatalyst is loaded on TiO surface, a spontaneous free-electron transfer from ReS to TiO happens due to the smaller work function of ReS, causing an over-strong S-H bond. To prevent the over-strong S-H bonds of ReS in the ReS/TiO , a free-electron reversal transfer strategy is developed to weaken the strong S-H bonds via increasing the work function of ReS by incorporating O to produce ReOS cocatalyst.

Nanoflower-like graphitic carbon nitride aerogel: Artful cyanuric acid-controlled synthesis and enhanced photocatalytic hydrogen evolution activity.

The previously reported studies on cyanuric acid-assembly strategy usually ignores the promoting function of cyanuric acid in the production of g-CN, limiting the development of molecular assembly strategies. In this study, a cyanuric acid-controlled synthesis strategy involving the pre-assembly of cyanuric acid with melamine and subsequent one-step calcination was developed to produce a three-dimensional (3D) nanoflower-like graphitic carbon nitride (g-CN) aerogel. Some cyanuric acid molecules underwent a polycondensation reaction with melamine during the pre-assembly process and finally polymerized into the g-CN structure during subsequent calcination.

Triggering the Channel-Sulfur Sites in 1T'-ReS Cocatalyst toward Splendid Photocatalytic Hydrogen Generation.

Electron density manipulation of active sites in cocatalysts is of great essential to realize the optimal hydrogen adsorption/desorption behavior for constructing high-efficient H -evolution photocatalyst. Herein, a strategy about weakening metal-metal bond strength to directionally optimize the electron density of channel-sulfur(S) sites in 1T' Re Mo S cocatalyst is clarified to improve their hydrogen adsorption strength (S─H bond) for rapid H -production reaction. In this case, the ultrathin Re Mo S nanosheet is in situ anchored on the TiO surface to form Re Mo S /TiO photocatalyst by a facial molten salt method.

Amine-Aldehyde Condensation-Derived N-Doped Hard Carbon Microspheres for High-Capacity and Robust Sodium Storage.

Hard carbon is generally accepted as the choice of anode material for sodium-ion batteries. However, integrating high capacity, high initial Coulombic efficiency (ICE), and good durability in hard carbon materials remains challenging. Herein, N-doped hard carbon microspheres (NHCMs) with abundant Na adsorption sites and tunable interlayer distance are constructed based on the amine-aldehyde condensation reaction using m-phenylenediamine and formaldehyde as the precursors.

Reversing Free-Electron Transfer of MoS Cocatalyst for Optimizing Antibonding-Orbital Occupancy Enables High Photocatalytic H Evolution.

The interaction between a co-catalyst and photocatalyst usually induces spontaneous free-electron transfer between them, but the effect and regulation of the transfer direction on the hydrogen-adsorption energy of the active sites have not received attention. Herein, to steer the free-electron transfer in a favorable direction for weakening S-H bonds of sulfur-rich MoS , an electron-reversal strategy is proposed for the first time. The core-shell Au@MoS cocatalyst was constructed on TiO to optimize the antibonding-orbital occupancy.

A Bifunctional CdS/MoO /MoS Catalyst Enhances Photocatalytic H Evolution and Pyruvic Acid Synthesis.

The best use of photogenerated electrons and holes is crucial to boosting photocatalytic activity. Herein, a bifunctional dual-cocatalyst-modified photocatalyst is constructed based on CdS/MoO /MoS hollow spheres for hydrogen evolution coupled with selective pyruvic acid (PA) production from lactic acid (LA) oxidation. MoS and MoO are simultaneously obtained from the conversion of CdMoO in one step.

Improved H-adsorption ability of Cu in CuNi alloy nanodots toward the efficient photocatalytic H-evolution activity of TiO.

Compared with the noble metal Pt, the non-noble metal Cu as a cocatalyst exhibits a low hydrogen-evolution activity owing to its weak Cu-H bond (11 kcal mol), which inhibits hydrogen adsorption on Cu atoms for the hydrogen-evolution reaction of photocatalysts. Considering that the introduction of Ni with a strong Ni-H bond into Cu is beneficial for strengthening the H-adsorption ability of Cu, in this paper, the low-cost transition-metal Ni was directly introduced into Cu to form CuNi alloy nanodots as photocatalytic cocatalysts to enhance the hydrogen-evolution rate of TiO. The CuNi alloy nanodots (2-3 nm) were photodeposited on the surface of a reduced graphene oxide (rGO)-modified TiO photocatalyst to generate CuNi-rGO/TiO by the pre-adsorption of Cu and Ni ions on graphene oxide (GO).

Dispersible CdSSe solid-solution nanocrystal photocatalysts: Photoinduced self-transformation synthesis and enhanced hydrogen-evolution activity.

Modulating the electronic structure of Cadmium sulfide (CdS) by non-metallic elements to produce solid-solution photocatalysts serves as a potential route to improve its performance of photocatalytic hydrogen (H) evolution. However, exploring an effective synthetic route of CdS-based solid solution is still a great challenge. Herein, the CdSSe solid-solution nanocrystals were successfully synthesized by an accessible photoinduced self-transformation route, including the direct formation of dispersible CdS(SeS) and the in situ self-transformation of selenosulfide ((SeS)) to Se by photoexcited electrons.

Emerging S-Scheme Photocatalyst.

Photocatalysis is a green technology to use ubiquitous and intermittent sunlight. The emerging S-scheme heterojunction has demonstrated its superiority in photocatalysis. This article covers the state-of-the-art progress and provides new insights into its general designing criteria.

Photocatalytic H Evolution Coupled with Furfuralcohol Oxidation over Pt-Modified ZnCdS Solid Solution.

Coupling photocatalytic H production with organic synthesis attracts immense interest in the energy and chemical engineering field for the low-cost, clean, and sustainable generation of green energy and value-added products. Nevertheless, the performance of current photocatalysts is greatly limited by grievous charge recombination and tardy H evolution. To tackle these issues, a Pt nanocluster-modified ZnCdS solid solution is fabricated for photocatalytic H production and selective furfuralcohol oxidation.

Optimizing Atomic Hydrogen Desorption of Sulfur-Rich NiS Cocatalyst for Boosting Photocatalytic H Evolution.

Low-cost transition-metal chalcogenides (MS ) are demonstrated to be potential candidate cocatalyst for photocatalytic H generation. However, their H -generation performance is limited by insufficient quantities of exposed sulfur (S) sites and their strong bonding with adsorbed hydrogen atoms (SH ). To address these issues, an efficient coupling strategy of active-site-enriched regulation and electronic structure modification of active S sites is developed by rational design of core-shell Au@NiS nanostructured cocatalyst.

Cyano group-enriched crystalline graphitic carbon nitride photocatalyst: Ethyl acetate-induced improved ordered structure and efficient hydrogen-evolution activity.

The molten salt-assisted route is one of the most important methods to improve the crystallinity of conventionally disordered bulk graphitic carbon nitride (g-CN). However, the residual potassium ions from potassium chloride/lithium chloride molten salt can greatly impact the ordered structure of g-CN and serve as the recombination centers of photoinduced carriers, causing limited photocatalytic hydrogen-evolution performance. In this article, the ethyl acetate-mediated method is first developed to not only further improve the ordered structure of traditional crystalline g-CN, but also produce more cyano groups for preparing highly efficient g-CN photocatalysts.

Inorganic Metal-Oxide Photocatalyst for H O Production.

Hydrogen peroxide (H O ) is a mild but versatile oxidizing agent with extensive applications in bleaching, wastewater purification, medical treatment, and chemical synthesis. The state-of-art H O production via anthraquinone oxidation is hardly considered a cost-efficient and environment-friendly process because it requires high energy input and generates hazardous organic wastes. Photocatalytic H O production is a green, sustainable, and inexpensive process which only needs water and gaseous dioxygen as the raw materials and sunlight as the power source.

Hydroxyl-enriched highly crystalline TiO suspensible photocatalyst: facile synthesis and superior H-generation activity.

A hydroxyl-enriched highly crystalline TiO suspensible photocatalyst was synthesized via a facile ethanol-controlled hydrolysis and following an in situ crystallization method. In the absence of any cocatalysts, the resultant photocatalyst displayed a clearly higher H-evolution rate (622 μmol h g) than the well-known commercial P25 TiO (190 μmol h g).

Design, Fabrication, and Mechanism of Nitrogen-Doped Graphene-Based Photocatalyst.

Solving energy and environmental problems through solar-driven photocatalysis is an attractive and challenging topic. Hence, various types of photocatalysts have been developed successively to address the demands of photocatalysis. Graphene-based materials have elicited considerable attention since the discovery of graphene.

Ultra-small molybdenum sulfide nanodot-coupled graphitic carbon nitride nanosheets: Trifunctional ammonium tetrathiomolybdate-assisted synthesis and high photocatalytic hydrogen evolution.

The preparation of nanoscale molybdenum sulfide (MoS)-modified graphitic carbon nitride (g-CN) nanosheets usually contains complex and multiple-step operations, including the separate synthesis of nanoscale MoS and g-CN nanosheet, and their subsequent composite process. To effectively overcome the above drawbacks, herein, a facile one-step trifunctional ammonium tetrathiomolybdate ((NH)MoS)-assisted approach has been designed to produce ultra-small MoS nanodot-coupled g-CN nanosheet photocatalyst, including the first addition of ammonium chloride (NHCl) and (NH)MoS into melamine precursors and their following one-step calcination. During high-temperature calcination, except for the promoting generation of the g-CN nanosheets by produced ammonia (NH) and hydrogen sulfide (HS) gases, the above (NH)MoS decomposition not only can efficiently clip the s-heptazine framework to produce more terminal amino groups and cyano groups, but also can produce ultra-small MoS nanodots on the resultant g-CN nanosheet surface, resulting in the final production of ultra-small MoS nanodot-coupled g-CN nanosheets.

Colloidal CdS and CdZnS nanocrystal photocatalysts with massive S-adsorption: one-step facile synthesis and highly efficient H-evolution performance.

Colloidal CdS and CdZnS nanocrystals (NCs) with massive S-adsorption were synthesized via a one-step synthetic method. In the absence of a cocatalyst, the as-obtained colloidal CdS-NC photocatalyst achieves a superb H-evolution rate of 6.86 mmol h g and an apparent quantum efficiency of 52.