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Defects engineering is significant for photocatalytic environment remediation. To this end, visible‐light‐driven α‐Fe2O3/ZrO2‐x S‐scheme heterojunction photocatalysts with optimal oxygen vacancy (Ov) defects are successfully synthesized via a two‐step method. Compared with pristine UiO‐66‐NH2‐derived ZrO2‐x and α‐Fe2O3, the heterojunction photocatalysts exhibit a wider range of visible light response and higher efficiency in separating photogenerated electron–hole pairs. Among them, the 5% α‐Fe2O3/ZrO2‐x sample shows the best photocatalytic performance to the degradation of tetracycline (TC) (89.3%), in which the pseudo‐first‐order kinetic rate constants are 8.20 and 16.75 times that of pristine ZrO2‐x and α‐Fe2O3, respectively. The outstanding photocatalytic degradation efficiency can be attributed to both the narrow‐bandgap ZrO2‐x with visible light response and the formation of α‐Fe2O3/ZrO2‐x S‐scheme heterojunctions. During the formation of heterojunctions, the concentration of oxygen vacancies (Ov) at the interface of α‐Fe2O3/ZrO2‐xdecreases monotonically with the increasing loading of α‐Fe2O3, thereby altering the electronic structure of the photocatalyst and forming the heterojunction firmly. In addition, the high stability implies the potential applications in fields of environment. [ABSTRACT FROM AUTHOR]

As a low-cost, low toxicity and metal-free catalyst with strong light absorption, graphitic carbon nitride (g-C3N4)-based materials have gained wide attention for efficient H2O2 photocatalysis. However, further investigation regarding the charge transfer process and reaction mechanism of H2O2 photoproduction remains to be completed. In this work, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BTDA) modified g-C3N4 is synthesized through a facile one-step dehydration process, and the H2O2 photoproduction could reach 22.5 μmol within 8 hours. The proposed structure of g-BTDA is confirmed by FTIR, XPS and SEM studies. The transient absorption reveals a 20.88 ps charge transfer process caused by the electron withdrawing ability of the C＝O group, and a 2-electron oxygen reduction pathway is proposed. Our work represents a new strategy for efficient H2O2 photoproduction using easily acquired materials with future application potential. [ABSTRACT FROM AUTHOR]

As a low-cost, low toxicity and metal-free catalyst with strong light absorption, graphitic carbon nitride (g-C3N4)-based materials have gained wide attention for efficient H2O2 photocatalysis. However, further investigation regarding the charge transfer process and reaction mechanism of H2O2 photoproduction remains to be completed. In this work, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BTDA) modified g-C3N4 is synthesized through a facile one-step dehydration process, and the H2O2 photoproduction could reach 22.5 μmol within 8 hours. The proposed structure of g-BTDA is confirmed by FTIR, XPS and SEM studies. The transient absorption reveals a 20.88 ps charge transfer process caused by the electron withdrawing ability of the C＝O group, and a 2-electron oxygen reduction pathway is proposed. Our work represents a new strategy for efficient H2O2 photoproduction using easily acquired materials with future application potential. [ABSTRACT FROM AUTHOR]

Actiniae‐like carbon nitride (ACN) bundles were synthesized by the pyrolysis of an asymmetric supramolecular precursor prepared from L‐arginine (L‐Arg) and melamine. ACN has adjustable band gaps (2.25 eV–2.75 eV) and hollow microtubes with ultrathin pore walls, which enrich reaction sites, improve visible‐light absorption and enhance charge separation. In the presence of phenylcarbinol, ACN exhibited excellent water‐splitting ability (95.3 μmol h−1) and in the meanwhile phenylcarbinol was selectively oxidized to benzaldehyde (conversion of 90.9 %, selectivity of 99.7 %) under solar irradiation. For the concurrent reactions, 2D isotope labeling, separation, and detection were conducted to confirm that the proton source of released hydrogen is water. The mechanism of water splitting and phenylcarbinol oxidation was also investigated. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (GCN) has become an attractive photocatalyst for solar energy conversion, but the photocatalytic activity of GCN is still limited by the extremely fast electron–hole recombination. Herein, a defective ultrathin mesoporous graphitic carbon nitride (DUMCN) photocatalyst with high specific surface area and mesoporous structure is fabricated through a facile three‐step heat‐treatment strategy, which reduces the distance of bulk photogenerated carriers to the surface, resulting in efficient adsorption and diffusion of reactants and products, and exposing adequate surface active sites. Moreover, suitable N‐vacancy defects are formed via high‐temperature surface hydrogenation, which can extend light absorption and produce ultra‐high intrinsic carrier mobility, and further increase the active sites. The photocatalytic hydrogen production rate is up to 13.63 mmol h−1 g−1 under visible light in the triethanolamine solution and 33.5 μmol h−1 g−1 for overall water splitting, which is much higher than that of bulk graphitic carbon nitride (BCN) structures. Density functional theory (DFT) calculations further reveal the effect of surface defects on the band structure for promoting the spatial charge separation. This facile strategy may offer new insights into designing other ultrathin mesoporous semiconductor photocatalysts with high performance. [ABSTRACT FROM AUTHOR]

The intriguing features of two-dimensional (2D) materials such as better charge carrier separation and abundant surface reaction sites endow them with potential applications as cocatalysts in photocatalysis. In this paper, a ternary 2D nickel hydroxide/sulfides nanosheet composed of Ni(OH) 2 , Ni 3 S 2 and Ni x S 6 was loaded on CdS nanospheres by a simple chemical deposition route. The composition of nickel hydroxide/sulfides was determined clearly through an overall analysis using X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Mott-Schottky, electrochemical impedance, steady-state and time-resolved photoluminescence spectroscopy were used to investigate the charge transfer process in CdS and Ni(OH) 2 /Ni 3 S 2 /Ni x S 6 -CdS. The results confirm that a synergistic effect of Ni(OH) 2 /Ni 3 S 2 /Ni x S 6 on CdS has occurred under light irradiation, where the Ni(OH) 2 and nickel sulfides act as hole storage and surface reaction sites, respectively, to promote the charge transfer on CdS. The improved charge transfer and separation efficiency as well as the increased surface reaction sites in Ni(OH) 2 /Ni 3 S 2 /Ni x S 6 -CdS finally result in a dramatically improved photocatalytic performance. The photocatalytic H 2 evolution rate of Ni(OH) 2 /Ni 3 S 2 /Ni x S 6 -CdS is ca . 46 times higher than that of CdS, and the photocatalytic stability of CdS is also improved substantially under visible light irradiation. [ABSTRACT FROM AUTHOR]

The solid-state Z-scheme trinary/binary heterostructures show the advantage of utilizing the high-energy photogenerated charge carriers in photocatalysis. However, the key factors controlling such Z-scheme in the binary heterostructures are still unclear. In this paper, we showed that oxygen vacancies could act as an interface electron transfer mediator to promote the direct Z-scheme charge transfer process in binary semiconductor heterostructures of CdS/ZnS. Increasing the concentration of surface oxygen vacancies of ZnO crystal can greatly enhance photocatalytic hydrogen generation of CdS/ZnO heterostructure. This was attributed to the strengthened direct Z-scheme charge transfer process in CdS/ZnO, as evidenced by steady-state/time-resolved photoluminescence spectroscopy and selective photodeposition of metal particles on the heterostructure. [ABSTRACT FROM AUTHOR]

Carbon nitride, phenylcarbinol oxidation, photocatalysis, supramolecular assembly, water splitting Keywords: carbon nitride; phenylcarbinol oxidation; photocatalysis; supramolecular assembly; water splitting EN carbon nitride phenylcarbinol oxidation photocatalysis supramolecular assembly water splitting 5003 5003 1 02/18/21 20210223 NES 210223 B Die synchrone und effiziente b Nutzung von photogenerierten Elektronen und Löchern ist eine herausfordernde Aufgabe auf dem Gebiet der Photokatalyse. Innenrücktitelbild: Ultrathin Porous Carbon Nitride Bundles with an Adjustable Energy Band Structure toward Simultaneous Solar Photocatalytic Water Splitting and Selective Phenylcarbinol Oxidation (Angew. [Extracted from the article]

Nanoformulations with endogenous/exogenous stimulus‐responsive characteristics show great potential in tumor cell elimination with minimal adverse effects and high precision. Herein, an intelligent nanotheranostic platform (denoted as TPZ@Cu‐SnS2‐x/PLL) for tumor microenvironment (TME) and near‐infrared light (NIR) activated tumor‐specific therapy is constructed. Copper (Cu) doping and the resulting sulfur vacancies can not only improve the response range of visible light but also improve the separation efficiency of photogenerated carriers and increase the carrier density, resulting in the ideal photothermal and photodynamic performance. Density functional theory calculations revealed that the introduction of Cu and resulting sulfur vacancies can induce electron redistribution, achieving favorable photogenerated electrons. After entering cells through endocytosis, the TPZ@Cu‐SnS2‐x/PLL nanocomposites show the pH responsivity property for the release of the TPZ selectively within the acidic TME, and the released Cu2+ can first interact with local glutathione (GSH) to deplete GSH with the production of Cu+. Subsequently, the Cu+‐mediated Fenton‐like reaction can decompose local hydrogen peroxide into hydroxyl radicals, which can also be promoted by hyperthermia derived from the photothermal effect for tumor cell apoptosis. The integration of photoacoustic/computed tomography imaging‐guided NIR phototherapy, TPZ‐induced chemotherapy, and GSH‐elimination/hyperthermia enhanced chemodynamic therapy results in synergistic therapeutic outcomes without obvious systemic toxicity in vivo. [ABSTRACT FROM AUTHOR]

Mesoporous TiO 2 nanospheres with engineered surface defects are fabricated through surfactant-mediated self-assembly solvothermal approach combined with surface hydrogenation, which exhibit excellent solar-driven photocatalytic hydrogen evolution, due to surface defects induced charge imbalance improving charge separation, and unique spherical mesoporous structure supplying adequate surface-active sites and facilitating mass transfer. [Display omitted] • Surface defects induced charge imbalance promote charge separation. • Mesoporous TiO 2 nanospheres with engineered surface defects are fabricated. • Nanoscale mesoporous spheres have closed packing and low surface energy. • It exhibits excellent solar-driven photocatalytic H 2 evolution and high stability. • Surface defects and mesostructure favor charge separation and mass transfer. Low charge separation efficiency of semiconductor materials is the main obstacle for high-performance photocatalyst. Herein, we report surface defects engineered uniform mesoporous TiO 2 nanospheres (DMTNSs) through surfactant-mediated self-assembly solvothermal approach combined with hydrogenation strategy to promote charge separation. The surface defects induced charge imbalance result in the formation of built-in field, which can promote photogenerated charge separation efficiently and be confirmed by experimental and density functional theory (DFT) calculations. Under AM 1.5G irradiation, the photocatalytic hydrogen evolution of DMTNSs is ~3.34 mmol h−1 g−1, almost 3.5 times higher than that of pristine non-defective TiO 2 nanospheres (0.97 mmol h−1 g−1), due to the engineered surface defects narrowing the bandgap (~3.01 eV) and inducing charge imbalance to boost spatial charge separation and extend visible-light response. The defect induced charge imbalance strategy opens a new valuable perspective for fabricating other high-efficient oxide photocatalysts. [ABSTRACT FROM AUTHOR]

Oxygen-defective Bi 2 MoO 6 /g-C 3 N 4 hollow tubulars S-scheme heterojunctions are fabricated by hydrothermal and calcination methods and show excellent photocatalytic performance. The S-Scheme heterojunction accelerates the effective charge separation and transfer by internal electric field (IEF) and energy band bending at the interface, thus improving the photocatalytic performance. [Display omitted] Novel S-scheme heterojunction photocatalysts of bismuth molybdate/hollow tube graphite carbon nitride (Bi 2 MoO 6 SOVs/g-C 3 N 4) containing surface defects (SOVs) were prepared by calcination and hydrothermal methods. The hollow tubular structure of g-C 3 N 4 facilitates the enhancement of multiple reflection and scattering of light, and also have a larger range of specific surface areas and more reactive sites, which promotes carrier separation and thus improves photocatalytic performance. The introduction of SOVs to bismuth molybdate not only reduces the band gap of bismuth molybdate, but also promotes the separation of charges. The optimized Bi 2 MoO 6 SOVs/TCN photocatalyst has a hydrogen production efficiency of 2.29 mmol h−1 g−1. It also shows high photocatalytic degradation property of tetracycline and bisphenol A in water, up to 97.3 % and 98.9 %, respectively. Meanwhile, the transfer mechanism of photogenerated charges in S-scheme heterojunctions can be verified by electron paramagnetic resonance and in situ irradiated x-ray photoelectron spectroscopy electron paramagnetic resonance, which accelerated the separation and transfer of photogenerated charge by energy band bending at the interface and internal electric field. This rational structural design strategy provides a new development idea for building high-performance S-scheme heterojunction photocatalysts. [ABSTRACT FROM AUTHOR]

Hetero-element doping or vacancy defects of g-C 3 N 4 framework were found significantly to control its electronic structure and enhance photocatalytic activity under visible light. Herein, we fabricated P-doped tubular g-C 3 N 4 (P-TCN) with surface carbon defects wherein the P-doping and carbon defects were conveniently introduced during thermal polymerization of a supramolecular precursor. The supramolecular precursor of rod-like morphology was obtained only from melamine molecules under a sodium pyrophosphate-assisted hydrothermal process. As contrast, similar P-doped g-C 3 N 4 tubes were obtained using other phosphates, such as ammonium phosphate, sodium hypophosphite and sodium phosphite, thus highlighting the versatility of this method to tune the morphology and C/N ratio for g-C 3 N 4 tubes. The photocatalytic activities of P-TCNs were evaluated using hydrogen evolution from water under visible light. Among these, P-TCN obtained by sodium pyrophosphate-assisted hydrothermal reaction showed the highest photocatalytic activity due to high P element doping, enhanced visible light absorption and improved charge separation. The novel synthetic method described here thus represents an effective way of non-metal doping and C/N ratio tuning of g-C 3 N 4 with excellent photocatalytic performance. [ABSTRACT FROM AUTHOR]

Ag-polydopamine nanoparticles co-decorated defective mesoporous carbon nitride assembly with wide spectrum response is fabricated, which exhibits robust photothermal-photocatalytic H 2 production, due to Ag-PDA not only extends the light absorption of DCN, but also forms an efficient Z-scheme charge transfer path with DCN, enabling fast electron transfer. [Display omitted] • Ag-polydopamine nanoparticles co-decorated defective mesoporous carbon nitride assemblies are fabricated. • Ag-polydopamine nanoparticles co-decorated promote efficient charge transfer. • Small-sized Ag nanoparticles as efficient cocatalysts enables efficient charge separation. • Ag-polydopamine extends photoabsorption and produces obvious photothermal effect to improve catalyze activity. • The formation of Z-scheme charge transfer mechanism favors spatial charge separation. Ag-polydopamine nanoparticles co-decorated defective mesoporous carbon nitride nanosheets assemblies (Ag-PDA/DCN) with wide spectrum responseare fabricated. The Ag-PDA/DCN assemblies exhibit excellent photocatalytic hydrogen production performance. The visible light and near-infrared light driven photocatalytic hydrogen evolution rate is up to 3840 μmol h−1 g−1, which is 20 and 7 times higher than those of DCN and PDA/DCN, respectively. This is mainly because the Ag-polydopamine nanoparticles not only form an efficient carrier transport path and realize fast electron transport, but also further extend the photoresponse of DCN, resulting in an obvious photothermal effect to further improve the photocatalytic activity. More importantly, the formed Ag nanoparticles by the low-temperature photodeposition method is smaller in size and better in dispersibility. Ag nanoparticles act as a co-catalyst in Ag-PDA/DCN, which can effectively separate the spatially photogenerated charge carriers. Compared to three systems with different Ag decoration positions, Ag-PDA/DCN with Z-scheme charge transfer mechanism is more favorable for promoting photocatalytic performance. This co-decorated strategy provides a new idea for developing low-cost Pt-free photocatalysts for solar energy conversion. [ABSTRACT FROM AUTHOR]

Polydopamine/defective ultrathin mesoporous graphitic carbon nitride Z-scheme organic assembly is fabricated via N -vacancy defects and π-π interactions, which exhibits robust photocatalytic H 2 production and contaminant degradation, due to the direct Z-scheme charge transfer mechanism to realize efficient spatial charge separation, and the enhanced photothermal effect to promote the photocatalytic reaction. [Display omitted] • Polydopamine/defective ultrathin mesoporous graphitic carbon nitride organic assemblies are fabricated. • N -vacancy and π-π interactions provide strong connection and fast charge transfer. • Z-scheme structure enables efficient of photogenerated charges separation. • Polydopamine extends photoabsorption and produces photothermal effect to improve catalyze activity. Polydopamine/defective ultrathin mesoporous graphitic carbon nitride (PDA/DCN) Z-scheme organic assembly is fabricated through high-temperature surface hydrogenation and ultrasonic freeze-dried strategies. PDA could be anchored on the surface of DCN with adequate N -vacancy defects firmly via π-π interactions, forming Z-scheme heterogenous structure for promoting charge separation. The visible and near-infrared light driven photocatalytic hydrogen evolution rate is up to 3420 μmol h−1 g−1, and the removal ratio of organic contaminant methylene blue is up to 98% within 70 min, which is several times higher than that of pristine graphitic carbon nitride and DCN. The important reason is the defects of DCN not only enhance the interaction with PDA, but also make the obvious polarized inbuilt electric field, and lead to Z-scheme structure for effective charge separation and rapid transfer, which is also confirmed by density functional theory (DFT) calculations. In addition, PDA extends the photoresponse to the near-infrared region and induces obvious photothermal effect to increase the reaction rate of the photocatalytic system. The efficient photothermal conversion of PDA/DCN should be another reason for the enhanced photocatalytic performance. [ABSTRACT FROM AUTHOR]

Ni/ZnIn 2 S 4 nanosheet assembly with sulfur vacancy and Schottky junction (Ni/DZIS) is fabricated and shows much better the photocatalytic hydrogen evolution rate without any noble metal cocatalysts. The improved photocatalytic performance is mainly attributed to the synergism of sulfur vacancy and Schottky junction accelerating the photogenerated charge transfer and thus inhibiting the charge recombination. [Display omitted] • Fabrication of Ni/ZnIn 2 S 4 nanosheet assembly with sulfur vacancy and Schottky junction (Ni/DZIS) through facile ethanediol-assisted solvothermal method. • The location of Ni at the hollow site of three S atoms next to sulfur vacancy on the ZnIn 2 S 4 (0 0 6) face. • The photocatalytic hydrogen evolution rate of Ni/DZIS up to 703 μmol g−1h−1 without any noble metal cocatalysts. Surface and interface engineering play vital roles on improving the photocatalytic hydrogen evolution. Herein, Ni/ZnIn 2 S 4 nanosheet assembly with sulfur vacancy and Schottky junction (Ni/DZIS) is fabricated through facile ethanediol-assisted solvothermal method. Density functional theory (DFT) calculation reveals that the Ni is absorbed at the hollow site of three S atoms next to sulfur vacancy on the ZnIn 2 S 4 (0 0 6) face due to the formation of sulfur vacancy. The resultant Ni/DZIS Schottky junction exhibits high photocatalytic H 2 evolution rate of 703 μmol g−1h−1 without any noble metal cocatalysts, which is 2.6 times higher than that of pristine ZnIn 2 S 4 nanosheets. The improved photocatalytic performance is mainly attributed to the synergism of sulfur vacancy and Schottky junction accelerating the photogenerated charge transfer and thus inhibiting the charge recombination. Moreover, the photocatalytic performance of Ni/DZIS nearly keeps constant even after six recycles, indicating the high stability and potential applications in field of energy. This work provides a convenient strategy for constructing efficient defective heterojunction assembly photocatalysts via surface and interface engineering. [ABSTRACT FROM AUTHOR]