Novel one-dimensional (1D) a-Fe 2 O 3 nanostructures containing a large amount of grain boundaries have been synthesized through the combination of electrospinning and precursor-calcination techniques. The as-prepared a-Fe 2 O 3 nanostructures were composed of orderly arranged building blocks (a-Fe 2 O 3 nanoparticles) which are connected to each other. The investigation of the morphology evolution revealed that the template fiber geometry has an influential impact on the grain growth behavior during preparation and thus the nanostructures of the final products. Different a-Fe 2 O 3 nanostructures (nanostrings and nanoropes) were synthesized using different PAN nanofibers as templates. These two samples are similar in microstructures but very different in grain boundary content. FT-IR spectra, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectra, UVvis diffuse reflection spectra and nitrogen adsorption-desorption analysis were used to characterize the structures of the synthesized products. Comparative ethanol sensing measurements between the a-Fe 2 O 3 nanostrings and nanoropes were conducted. The nanoropes which contain more grain boundaries showed a 3 to 4-time enhancement in ethanol response compared to the nanostrings. The results prove that creating a large amount of well-ordered grain boundaries is an effective way to enhance the sensing performance. ; Tel: +86 21 65982620 † Electronic supplementary information (ESI) available: Further details include SEM images of Fe 2 O 3 nanobers calcined at 600 C in air from the A-PAN-Fe precursor with the different immersion times; TG-DSC analysis of the A-PAN 1 -Fe and A-PAN 2 -Fe; XRD diffraction patterns of samples calcined at various temperatures; SEM images of the a-Fe 2 O 3 nanostrings and nanoropes aer calcination at various temperatures; response of a-Fe 2 O 3 nanostrings and nanoropes to different concentrations of C 2 H 5 OH at 240 C and cyclic sensing and recovery performance of a-Fe 2 O 3 nanostrings and nanoropes toward 100 ppm C 2 H 5 OH at 260 C. See

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Novel bimetallic metal–organic framework nanocomposites were fabricated by a facile yet efficient method. The as-prepared nanomaterial exhibited high sensitivity and high selectivity toward phosphopeptides and good reusability of five cycles for enriching phosphopeptides.