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Solar-driven interfacial evaporation has shown great promise for desalination due to its high photothermal conversion efficiency. However, for interfacial evaporation, the evaporator must have superior mechanical quality and strong thermal stability. To this end, ceramic nanofibrous mats with good mechanical strength can serve as a stable substrate for desalination. Herein, with the aid of finite element analysis, flexible Al2O3/TiO2 nanofibrous mats with robust mechanical properties are fabricated, where the stress dispersion greatly facilitates the Al2O3/TiO2 nanospheres to be uniformly dispersed into the mat. The flexible nanofibrous mats exhibit a high tensile strength up to 2.18 MPa. Afterward, a two-dimensional (2D) Al2O3/TiO2/MXene mat is constructed by a simple drop-casting method. Interestingly, the evaporation rate of the Al2O3/TiO2/MXene-2 mat reached 1.43 kg m−2 h−1, and the light-to-vapor energy conversion efficiency can reach 102% at a power density of 1.0 kW m−2. To measure the desalination efficiency, five ion concentrations in the collected water were found to be well below the safe salinity levels defined by standards set by the World Health Organization and U.S Environmental Protection Agency. Utilizing basic origami technology, the three-dimensional (3D) photothermal evaporator was integrated with the 2D mat due to its flexibility and ductility. Additionally, the evaporation rate increased to 1.61 kg m−2 h−1. This study is critical in the design of composite ceramic nanofiber materials with high flexibility and photothermal conversion efficiency for multifunctional desalination. [ABSTRACT FROM AUTHOR]

Supported metal catalysts are critical to many important chemical reactions, but the weak metal/support interaction is an obstacle to the success of remarkable catalytic performance. This paper reports rational-designed novel Pt supports, consisting of reduced graphene oxide sheets decorated with both Fe2O3 nanorods and N-dopants (denoted as Fe2O3/N-RGO), for Pt photodeposition driven by visible light in a controllable fashion. The 2-3 nm Pt nanocrystals primarily nucleated on rough Fe2O3 nanorods, and interacted strongly with special sites on the Fe2O3 surface using unsaturated vacant orbitals. At the same time, the accelerated photodegradation of undesirable PVP allowed the Pt nanocrystals with clean active sites. The supported Pt showed impressive activity and had a 7-times higher reaction rate constant (11.4 s-1 mg-1) towards 4-nitrophenol reduction, compared with that of free Pt, due to the synergetic effect within the whole Pt/Fe2O3/N-RGO catalysts and the doping of N atoms which acted as new metal-free catalytic centers in N-RGO sheets. We further demonstrated that the ternary catalyst could be easily removed through magnetic separation from the system. This new strategy is extendible to other heterogeneous catalysts with different components. [ABSTRACT FROM AUTHOR]

For TiO2-based photoanodes, the interfacial coupling between TiO2 and conductive materials (e.g., carbon) plays a vital role in determining the electron transfer efficiency and thus photoelectrical performance. In this paper, we describe a facile approach to effectively engineering the interfacial coupling between reduced graphene oxide (RGO) and TiO2 in well-designed one-dimensional (1D) RGO-wrapped TiO2 nanofibers, which act as ultrafast electron transfer bridges when implanted in photoanodes. The 3–5 nm RGO nanoshells were hybridized with TiO2 nanofibers as an electron donor component via d–π electron orbital overlap between C and Ti atoms, by adopting a thermal reduction at 450 °C. Remarkable photoelectric improvement, in terms of high photocurrent density by 2.2-fold and ultralow charge transfer resistance (Rct) by 0.2-fold, is ascribed to the interfacial charge transfer. Completely reduced RGO in RGO/TiO2 nanofibers was not necessary at the expense of their hydrophilicity, as it led to unexpected isolation in the photoanodes. The thermal reduction temperature of RGO/TiO2 nanofibers was found to be critical, and a maximal photocurrent density could be achieved by 2.7-fold at 530 °C. An excess of RGO/TiO2 nanofibers of more than 5 wt% had a degrading effect on the photoelectrical activity, largely due to the light-block effect and isolation in the matrix. This strategy provides new insight for tuning the intrinsic chemical and/or physical properties of well-designed semiconductor nanostructures with promising photoactivities in highly efficient photovoltaic devices. [ABSTRACT FROM AUTHOR]