Following the successful experimental synthesis of single-layer metallic 1T-TaS₂ and semiconducting 2H-MoS₂, 2H-WSe₂, we perform a first-principles study to investigate the electronic and interfacial features of metal/semiconductor 1T-TaS₂/2H-MoS₂ and 1T-TaS₂/2H-WSe₂ van der Waals heterostructures (vdWHs) contact. We show that 1T-TaS₂/2H-MoS₂ and 1T-TaS₂/2H-WSe₂ form n-type Schottky contact (n-ShC type) and p-type Schottky contact (p-ShC type) with ultralow Schottky barrier height (SBH), respectively. This indicates that 1T-TaS₂ can be considered as an effective metal contact with high charge injection efficiency for 2H-MoS₂, 2H-WSe₂ semiconductors. In addition, the electronic structure and interfacial properties of 1T-TaS₂/2H-MoS₂ and 1T-TaS₂/2H-WSe₂ van der Waals heterostructures can be transformed from n-type to p-type Schottky contact through the effect of layer spacing and the electric field. At the same time, the transition from Schottky contact to Ohmic contact can also occur by relying on the electric field and different interlayer spacing. Our results may provide a new approach for photoelectric application design based on metal/semiconductor 1T-TaS₂/2H-MoS₂ and 1T-TaS₂/2H-WSe₂ van der Waals heterostructures.

In this study, the synergetic effects in a Fenton-like system catalyzed by nano zero-valent iron (nZVI Fenton-like system) were studied using nitrobenzene (NB) as a model contaminant. The results showed that homogeneous and heterogeneous Fenton processes existed simultaneously in the nZVI Fenton-like system, and a synergetic removal effect between these processes played a considerable role in NB removal. Through quantitative analysis, 36.5% of NB degradation was attributed to the synergetic degradation effect, which was caused by a synergetic catalytic effect between nZVI and dissolved iron ions (Fe3+ and Fe2+). In the bulk solution, the Fe3+/Fe2+ redox rate was accelerated by nZVI, resulting in the efficiency improvement of homogeneous catalysis; in the surface of nZVI, these dissolved iron ions promoted the electrons transfer from nZVI core to shell, enhancing the efficiency of heterogeneous catalysis. The synergetic catalytic effect also improved the utilization-rate of H2O2 by reducing the decomposition caused by Fe3+/Fe2+ redox compared to that in the homogeneous Fenton system. Based on these results, a possible mechanism of synergetic effects in the nZVI Fenton-like system was proposed. These results could provide insight into an nZVI Fenton-like system.

Suitable electron transport layers are essential for high performance planar perovskite heterojunction solar cells. Here, we use ZnO electron transport layer sputtered under oxygen-rich atmosphere at room temperature to decrease the hydroxide and then suppress decomposition of perovskite films. The perovskite films with improved crystallinity and morphology are achieved. Besides, on the ZnO substrate fabricated at oxygen-rich atmosphere, open-circuit voltage of the CH₃NH₃PbI₃-based perovskite solar cells increased by 0.13 V. A high open-circuit voltage of 1.16 V provides a good prospect for the perovskite-based tandem solar cells. The ZnO sputtered at room temperature can be easily fabricated industrially on a large scale, therefore, compatible to flexible and tandem devices. Those properties make the sputtered ZnO films promising as electron transport materials for perovskite solar cells. 电子传输层对于N-I-P型平面钙钛矿太阳电池的性能至关重要. ZnO薄膜由于其高载流子迁移率在钙钛矿太阳电池中被广泛应用,但是薄膜内部羟基的存在影响了电池性能. 本文在磁控溅射沉积ZnO薄膜的过程中引入富氧环境来抑制ZnO中羟基的生成, 进而抑制钙钛矿薄膜的分解, 从而获得具有较高结晶质量的均匀致密的钙钛矿薄膜. 基于富氧环境下制备的ZnO作为电子传输层的钙钛矿太阳电池开压增加了0.13 V. 1.16 V的高开路电压对钙钛矿太阳电池在叠层电池中的应用提供了较好的发展前景. 此外, 室温磁控溅射制备的ZnO可以实现大面积工业化生产, 且适用于柔性和叠层器件. 该研究表明ZnO在太阳电池领域具有潜在应用.