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Photocatalytic hydrogen (H 2) evolution from water is considered as a prospective approach, which can convert inexhaustible solar energy into chemical energy to alleviate energy crisis and environmental problems. Herein, the N-defective g-C 3 N 4 with porous structure was firstly synthesized in a sealed crucible by one-step thermal polymerization method. The experimental data showed that the yield of the catalyst was obviously increased under sealing condition. Moreover, the N-defective g-C 3 N 4 prepared from urea precursor under sealed condition reached an optimum photocatalytic H 2 production rate of 597.4 μmol/h and an apparent quantum efficiency of 15.6% at wavelength of 420 nm. This enhanced photocatalytic H 2 production performance is mainly ascribed to the introduction of N-defects, which not only extended of the visible light absorption, but also acted as the electron trap centers to suppress the recombination of the photogenerated electron and hole pairs. This work offers one-step facile strategy for the introduction of N-defects to prepare N-defective g-C 3 N 4 with superior photocatalytic activity, which is also a great substitute for the high-energy consuming and complicated synthetic routes. • N-defective g-C 3 N 4 was prepared via one-step sealed ammonia self-etching strategy. • Produced ammonia molecules can etch the g-C 3 N 4 to form a porous thinner nanosheet. • N-defective g-C 3 N 4 can provide more reaction active sites for photocatalysis. [ABSTRACT FROM AUTHOR]

A Zn-P bond oriented black phosphorus/CuInZnS S-scheme heterojunction was successfully constructed for tetracycline (TC) degradation and synergistic H 2 generation. An enhanced photocatalytic H 2 revolution rate of 2056.0 μmol/h/g was achieved with triethanolamine (TEOA) as the hole sacrifice agent, which was nearly two times higher than that of CuInZnS (CIZS) and 170 times that of black phosphorus (BP). To further improve the hole utilization rate and reduce the energy consumption, an appropriate amount of TC was added instead of TEOA, and an improved photocatalytic H 2 generation rate of 1921.2 μmol/g was obtained with the synergistic degradation of TC by 82%. The types of heterojunctions and the transfer process of carriers were investigated by the combination of Mott-Schottky curves, Ultraviolet photoelectron spectroscopy, UV–vis diffuser reflectance spectra, and density functional theory. The results showed that a S-scheme heterojunction is built in BP/CIZS, which maintained the high redox ability of electron-hole pairs based on the successful separation of carriers. In addition, the novel Zn-P bond provided a charge transport channel and catalytic reaction active center upon photocatalysis. The design and application of photocatalysts proposed in this work offered a new idea for the coordinated resolution of environmental purification and energy conversion problems. • Zn-P bond induced BP/CIZS heterojunction was designed for waste to hydrogen conversion. • The hybrid has richer reactive sites, enhanced charge transfer and sunlight response ability. • Enhanced water splitting activity is achieved by the assistance of tetracycline. • A systematic study of photocatalytic mechanism was proposed. [ABSTRACT FROM AUTHOR]

Photocatalytic nitrogen fixation combined with degradation of organic pollutants is a promising technology to alleviate the growing energy and environmental crisis. In this work, Ti 3 C 2 T x /CuZnInS (TiC/CZIS) Schottky heterojunction difunctional photocatalytic was rationally designed for efficient nitrogen fixation synergistic bisphenol A (BPA) degradation. The Ti 3 C 2 T x ultra-thin nanosheets with richer surface-active groups and lower Fermi level greatly improved the carrier generation and separation ability of CZIS nanosphere. In addition, the coupling of TiC extended the absorption of CZIS to infrared region, which provided the possibility of efficient photocatalytic activity in cloudy and rainy days. As a result, an enhanced photocatalytic nitrogen fixation activity of 45.6 μmol/g/h was achieved. It should be noted that once appropriate amount of BPA was introduced to the photocatalytic system, a satisfied activity of 82.5 μmol/g/h was obtained, BPA can also be degraded by 58.5% within 180 min by TiC/CZIS. Through a series of experimental characterizations, the photocatalytic active substances and degradation pathway of BPA was investigated, and the possible photocatalytic mechanism was established. This work lays a foundation for the design of environmentally friendly photocatalysts and their applications in the fields of environmental purification and energy conversion. [Display omitted] • Ti 3 C 2 T x decorated CuZnInS was designed for waste to energy conversion. • The hybrid has richer reactive sites, enhanced charge transfer and sunlight response ability. • Enhanced nitrogen fixation activity is achieved by the assistance of BPA. • A systematic study of photocatalytic mechanism was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Studying the exciton dissociation is the key to revealing the photocatalytic mechanism. • The exciton-rich properties of BP QDs have special advantages in the process of charge separation. • BP QDs have many-body effect, short carrier transport distance and abundant reaction sites. • The BP/TiO 2 heterojunction exhibits excellent H 2 production efficiency (112 μmol·h−1·g−1). The Coulomb interactions between excited electrons and holes have a very important influence on the photophysical processes in 2D semiconductors. Exciton dissociation is one of the key steps that significantly contribute to the efficiency of photocatalysis, but its research in the relevant aspects of photocatalysis has not been in-depth. Herein, the BP/TiO 2 heterojunction as a prototypical model system was constructed on the surface of urchin-like TiO 2 where black phosphorous (BP) quantum dots (QDs) grew. The BP/TiO 2 heterojunction exhibits an improved H 2 -production rate of 112 μmol·h−1·g−1 under UV–visible light irradiation without any cocatalysts, which is 2.4 times higher than that of pure TiO 2 (47 μmol·h−1·g−1). As a typical exciton-rich material, BP QDs have special advantages on the charge separation process, because of their prominent many-body effect, short carrier transport distance, and large specific surface with rich reactive sites. The energy difference between the conduction bands turns out to be the driving force for exciton dissociation in the BP/TiO 2 heterojunction. The theoretical calculation implies that the excited electron tends to transfer from BP QD to TiO 2. The high catalytic performance of heterojunction contributes to the effective exciton dissociation, interfacial charge separation, and charge-carrier accumulation. This work lays the foundation for the design of the BP QDs based photocatalytic system and its application in photocatalytic hydrogen production and provides an effective reference for increasing the active sites of heterojunctions. [ABSTRACT FROM AUTHOR]

• NDs/UiO-66-NH 2 was prepared by a two-step route consisting of solvothermal and calcination; • Formation of NDs/UiO-66-NH 2 heterojunction can enhance separation of photo-generated carriers; • NDs/UiO-66-NH 2 exhibits the outstanding photocatalytic degradation activity of antibiotics. Photocatalytic degradation of antibiotics is one of promising strategies to lessen environmental pollution and ecological damage. Pitifully, it is still challenging to achieve satisfactory photocatalytic degradation performance. Herein, nanodiamonds (NDs) coated on the surface of UiO-66-NH 2 octahedrons to form NDs/UiO-66-NH 2 heterojunction photocatalyst via a simple solvothermal method. The synthesized NDs/UiO-66-NH 2 composite photocatalysts possess decent antibiotic degradation performance under visible light irradiation. Among all the composites, 3% NDs/UiO-66-NH 2 composite exhibits the optimal degradation performance, which degraded more than 90% of TC pollutants within 120 min, 8.81 times higher than pristine UiO-66-NH 2. The high photocatalytic performance of NDs/UiO-66-NH 2 heterojunction is mainly attributed to the following three factors: (i) the introduction of NDs effectively increased the light absorption capacity of UiO-66-NH 2 ; (ii) the Construction of heterojunction enhanced the separation efficiency of photogenerated carriers over UiO-66-NH 2 ; (iii) The enriched functional groups of NDs could further promote the adsorption capacity of UiO-66-NH 2. Our work broadens the application of NDs for the construction and synthesis of high-performance and stable semiconductor composite photocatalysts with visible light response in the area of environmental restoration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Z- Scheme Oxygen-rich vacancy TiO 2 /Ta 3 N 5 (Vo-TiO 2 /Ta 3 N 5) was development. • Vo-TiO 2 /Ta 3 N 5 can efficiently degrade CIP, ,MB, RhB and Staphylococcus aureus. • Intermediates in the degradation of ciprofloxacin were analyzed. • A possible photocatalytic mechanism is proposed. An oxygen-vacancy-rich TiO 2 /Ta 3 N 5 (Vo-TiO 2 /Ta 3 N 5) composite material was constructed via a solvothermal method, and the photocatalytic degradation of ciprofloxacin (CIP) performance was investigated in-depth. The solvothermal synthesis method introduces oxygen vacancies in TiO 2 , and successfully combines Vo-TiO 2 and Ta 3 N 5 to form a Z-Scheme structure. As a narrow bandgap semiconductor, Ta 3 N 5 increases the absorption of the catalyst in the visible light region. Oxygen vacancies form an intermediate energy level in TiO 2 , which promotes the separation of photogenerated electrons and holes. In addition, the Z-Scheme energy band structure formed by Vo-TiO 2 and Ta 3 N 5 enables more photogenerated carriers to participate in the photocatalytic reaction, so that the Vo-TiO 2 /Ta 3 N 5 heterojunction structure has excellent photocatalytic degradation of ciprofloxacin (CIP) performance. Furthermore, Vo-TiO 2 /Ta 3 N 5 also can degrade rhodamine B, Methylene Blue and kill Staphylococcus aureus. It demonstrates that the sample is a multifunctional catalyst. This research provides a basis for the development of new nanocomposite photocatalysts by combining defect engineering and heterostructure construction of two modified semiconductor methods. [ABSTRACT FROM AUTHOR]

[Display omitted] Design of highly efficient heterojunctions for photocatalytic hydrogen evolution is of significant importance to address the energy shortage and environmental crisis. Nevertheless, the smart design of semiconductor-based heterojunctions at the atomic scale still remains a significant challenge hitherto. Herein, we report novel atomic CdS/ZnIn 2 S 4 heterojunctions by in-situ epitaxially growing 2D ZnIn 2 S 4 nanosheets onto the surface of 1D defective CdS nanorods. The strong electronic coupling between defective CdS and ZnIn 2 S 4 is confirmed by transient photocurrent response measurements, •O 2 − and •OH radicals experiments, and PL results, leading to accelerated interfacial charge separation and transfer. Additionally, the elevated charge transfer and electronic coupling are further confirmed by theoretical calculations. Consequently, CdS/ZnIn 2 S 4 hybrids exhibit superior photocatalytic hydrogen generation activity to pristine CdS. Our findings offer a new paradigm for designing atomic 1D/2D heterojunctions for efficient solar-driven energy conversion. [ABSTRACT FROM AUTHOR]

Abstract: Aqueous‐solution‐processed solar cells (ASCs) are promising candidates of the next‐generation large‐area, low‐cost, and flexible photovoltaic conversion equipment because of their unique environmental friendly property. Aqueous‐solution‐processed polymer/nanocrystals (NCs) hybrid solar cells (AHSCs) can effectively integrate the advantages of the polymer (e.g., flexibility and lightweight) and the inorganic NCs (e.g., high mobility and broad absorption), and therefore be considered as an ideal system to further improve the performance of ASCs. In this work, double‐side bulk heterojunction (BHJ), in which one BHJ combines the active material with electron transport material and the other combines the active material with hole transport material, is developed in the AHSCs. Through comparing with the single‐side BHJ device, promoted carrier extraction, enhanced internal quantum efficiency, extended width of the depletion region, and prolonged carrier lifetime are achieved in double‐side BHJ devices. As a result, power conversion efficiency exceeding 6% is obtained, which breaks the bottleneck efficiency around ≈5.5%. This work demonstrates a device architecture which is more remarkable compared with the traditional only donor–acceptor blended BHJ. Under conservative estimation, it provides instructive architecture not only in the ASCs, but also in the organic solar cells (SCs), quantum dot SCs, and perovskite SCs. [ABSTRACT FROM AUTHOR]