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Unraveling how mid-gap state energy level of graphitic carbon nitride (g-C 3 N 4) promote near-infrared (NIR) driven photochemical energy conversion at the molecular level remains a grand challenge. Here, we report a series of S double-site-doped ultrathin g-C 3 N 4 nanosheets (SUCN) with adjustable intermediate band gap benefits from light response over NIR region. The SUCN produced after optimizing S double-site doping can effectively generate hydrogen (H 2) under NIR-light irradiation. The highest H 2 generation rate achieved was respectively 9.35 and 17.46 μmol g−1 h−1 under λ = 765 and λ > 800 nm, which is firstly expended photocatalytic activity of S-doped g-C 3 N 4 to NIR region beyond λ > 765 nm. We proposed a molecular-level method, i.e., the localized oxidation state of proton acceptor triethanolamine (TEOA) in the mid-gap state to ensure the NIR-driven H 2 generating behavior. [Display omitted] • g-C 3 N 4 was doped with S atoms at a specific site of the triazine skeleton. • S doping provides an adjustable intermediate band gap of g-C 3 N 4. • The 0.36-SUCN obtained 43 times higher PHE than g-C 3 N 4. • The S-doped g-C 3 N 4 firstly realized PHE in the near-infrared region. • The NIR-driven H 2 generation was firstly demonstrated by a molecular-level method. [ABSTRACT FROM AUTHOR]

Water-soluble deoxynivalenol (DON) pose a major threat as a potential organic pollutant to water environmental quality. DON is a toxic secondary metabolite produced by molds of the Fusarium genus and one of the most important mycotoxins in cereal commodities, which can be enriched from the contaminated grain by deoxynivalenol in the process of wet processing. In this work, graphene/ZnO hybrids has been successfully prepared via a simple one-step hydrothermal method and exhibited superior photocatalytic activity for the photodegradation of DON under the irradiation of UV light. The UV light photocatalytic activity of graphene/ZnO hybrid GZ0.3 was 3.1 times than pure ZnO and about 99% of DON (15 ppm) could be photodegraded within 30 min totally while there were three peaks of intermediate products appeared. The ESI/MS analysis confirmed the presence of DON and degradation product with the secondary mass spectrogram in the positive ESI mode. Overall, this work could provide new insights into the fabrication of graphene/ZnO hybrids composite as high performance photocatalysts and facilitate their application in the mycotoxin detoxification and environmental protection issues. [ABSTRACT FROM AUTHOR]

Novel visible-light-driven 2D-2D heterojunction photocatalysts was constructed based on 2D g-C 3 N 4 and exfoliated ultrathin K + Ca 2 Nb 3 O 10 − nanosheets, which is derived from Dion-Jacobson phase layer perovskites. The photocatalytic performance of the 2D-2D g-C 3 N 4 /K + Ca 2 Nb 3 O 10 − nanosheet heterojunctions was evaluated by the degradation of tetracycline hydrochloride under visible light irradiation. Compared with bare K + Ca 2 Nb 3 O 10 − and g-C 3 N 4 , the g-C 3 N 4 /K + Ca 2 Nb 3 O 10 − nanosheet heterojunctions exhibited considerably enhanced photocatalytic activity towards the degradation of tetracycline hydrochloride, which is about 6.6 and 1.8 times higher than that of pure K + Ca 2 Nb 3 O 10 − and g-C 3 N 4 , respectively. This enhanced activity can be mainly attributed to the synergistic effect of g-C 3 N 4 /K + Ca 2 Nb 3 O 10 − nanosheet heterojunctions with strong interfacial interaction and abundant 2D coupling interfaces, which could efficiently promote the photo-induced charge separation. The results of work demonstrated that construction of 2D-2D heterojunctions is an effective strategy to obtain the enhanced photocatalytic activity towards the degradation of tetracycline hydrochloride. [ABSTRACT FROM AUTHOR]

Visible-driven photocatalysis plays a critical role in solar energy conversion, but the efficiency is limited by the poor charge separation and utilization. Here, a ternary photocatalyst is constructed using Cu-In-Zn-S quantum dots (CIZS QDs), MoS 2 and carbon dots (CDs). Interestingly, transient photovoltage measurements confirm that MoS 2 has no assistance on the charge extraction rate, whereas CDs dramatically increases the attenuation constant of the charge recombination process (from 0.178 to 0.260 ms) due to its electron sinking effect. The optimal hydrogen production rate of CIZS/MoS 2 /CDs reaches 3706 μmol g-1 h-1, which is 6.65 and 148.24 times to that of CIZS QDs and MoS 2 , respectively. Further electrocatalytic tests indicate that MoS 2 is the main place for hydrogen evolution reaction, whereas CIZS and CDs are responsible for light harvesting and charge sinking, respectively. This work provides a useful guideline for the synergy of charge extraction and utilization process in composite photocatalyst design. Carbon dots are used for mediating highly efficient charge sinking, resulting in the increase of attenuation constant of surface charge carriers from 0.178 to 0.260 ms and 6.65 times enhancement of hydrogen evolution rate in CIZS/MoS 2 /CDs. [Display omitted] • Carbon-dots-mediated highly efficient charge sinking in CIZS/MoS 2 /CDs photocatalyst for hydrogen evolution. • The hydrogen production rate over the CIZS/MoS 2 /CDs has 6.65-fold increase over primal CIZS. • The attenuation constant of the surface charge carriers in CIZS/MoS 2 /CDs increases from 0.178 to 0.260 ms. [ABSTRACT FROM AUTHOR]