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Earth-abundant and ecofriendly minerals SnSxSe1–x can be promising candidates for photoelectrochemical (PEC) cells because of their tunable band gaps and high absorption efficiency. Metal nanoparticle-modified SnSxSe1–x enhance the efficiencies of solar energy water splitting. In this paper, SnSxSe1–x nanosheets (NSs) were prepared by a one-pot method and silver (Ag) nanoparticles were deposited on the surface of SnSxSe1–x NSs through a photochemical reduction process. The structural properties of SnSxSe1–x and SnSxSe1–x/Ag NSs were characterized by X-ray diffraction (XRD) and Raman spectroscopy. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the morphologies of SnSxSe1–x and SnSxSe1–x/Ag NSs. The band gaps of SnSxSe1–x and SnSxSe1–x/Ag NSs were determined using the UV–Vis–NIR spectra. PEC measurements indicated that the photocurrents of SnSxSe1–x thin films increased first and then decreased with the increase of Se. The SnS0.5Se0.5 thin films had the best PEC properties. The modification of Ag nanoparticles enhanced the PEC properties of SnSxSe1–x NSs. The highest photocurrent density of 69.3 μA/cm2 and the incident monochromatic photon-to-electron conversion efficiency (IPCE) of 27.9% were obtained. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) tellurium (Te) has drawn extensive interest for its intriguing properties, such as p-type conduction, high mobility, environmental stability, and field effects. Here, we employ a substrate-free solution method to prepare quasi-1D Te nanowires (TNWs) and 2D Te nanosheets (TNSes) to construct van der Waals heterojunctions with two-dimensional electron gas (2DEG) on SrTiO3 (STO). Such heterojunctions exhibit good rectifying behavior, indicating promising applications as diodes. The ratios of positive and negative currents reach as high as 103 for TNW/2DEG-STO and 107 for TNS/2DEG-STO. Such diodes show strong suffertibility to large negative voltages up to −100 V. Their high performances are found to cover a broad temperature range. In addition, the forward current of the TNW/2DEG-STO heterojunction shows a temperature dependence different from that of the TNS/2DEG-STO heterojunction. A main explanation is that the TNWs are more influenced by the edge effect than the TNSes, supported by electric force microscopy. [ABSTRACT FROM AUTHOR]