NiAl-W纳米多孔阵列制备方法研究

采用定向凝固与选择性腐蚀复合工艺,获得NiAl-W纳米多孔阵列。通过定向凝固速率可调节棒状NiAl-W共晶中棒状W相的间距和直径,电化学选择性腐蚀去除W相后,在NiAl基体表面上形成间距和孔径可调的多孔阵列。由于孔径尺度的限制,孔列在电势0.5V连续腐蚀2~3h后受到极大的阻力。

Design and construction of a film of mesoporous single-crystal rutile TiO_2 rod arrays for photoelectrochemical water oxidation

A film of mesoporous single-crystal rutile TiO2 rod arrays supported on a transparent conductive glass substrate was synthesized with the assistance of a template layer of closely packed silica nanospheres. This film was used as a photoanode and showed significant improvement for photoelectrochemical water oxidation compared with a reference film of nonporous single-crystal rutile TiO2rod arrays.

Nanopore DNA sequencing:Are we there yet?

Nanopores have been studied as a unique DNA sequencing technology that can quickly read long stretched DNA sequences. A DNA molecule could pass through a nanopore in a speed of microsecond per base and even faster. With this speed, a human genome can potentially be sequenced by one nanopore in 〈1 h. In contrast to next- generation DNA sequencing （NGS）, the nanopore sequencing is enzyme free without need of sample amplification due to its single-molecule nature. The nanopore sequencing has been envisioned as a new generation of DNA sequencing technology in the post-NGS era. This progress focuses on status quo of the nanopore DNA sequencing and discusses the opportunities and challenges in this rapidly growing field.

Surface enhanced fluorescence by porous alumina with nanohole arrays

The fluorescence enhancement of Rhodanfine 6G （Rh6G） fluorophore in the close vicinity of porous alumina film with ordered nanohole arrays is investigated. Experimental observations show that the nonmetallic substrate with hole arrays enhances the fluorescence intensity. By comparing the fluorescence emissions that are excited with 325 nm and 532 nm, better fluorescence enhancement is obtained with excitation at a shorter wavelength. The study suggests that higher fluorescence excitation effi- ciency due to the energy transfer from oxygen vacancies to Rh6G fluorophore molecules is responsible for better fluorescence enhancement. The contribution of the scattering of nanohole arrays to the fluorescence enhancement is also proposed based on the intensity increase and reduced lifetime when the energy transfer from oxygen vacancy is absent. The result of the current study is useful for developing non-metal substrates in the study of spectroscopic enhancement, and is expected to advance the applications of porous alumina to microanalysis.

Promoting charge carrier utilization by integrating layered double hydroxide nanosheet arrays with porous BiVO_4 photoanode for efficient photoelectrochemical water splitting

The increasing exploration of renewable and clean power sources have driven the development of highly active materials for photoelectrochemical （PEC） water splitting. However, it is still a great challenge to enhance the charge utilization. Herein, we report a facile method to fabricate composite photoanode with porous BiVO4 film as the photon absorber and layered double hydroxide （LDH） nanosheet arrays as the oxygen-evolution cocatalysts （OECs）. The as-prepared BiVO4/NiFe-LDH photoanode shows an excellent performance for PEC water splitting benefitting from the synergistic effect of the superior charge separation efficiency facilitated by porous BiVO4 film and the excellent water oxidation activity resulting from LDH nanosheet arrays. A photocurrent density is 4.02 mA cm^-2 at 1.23 V vs. the reversible hydrogen electrode （RHE）. Furthermore, the O2 evolution rate at the surface of BiVO4/NiFe-LDH photoanode is as high as 29.6 μmol h^-1 cm^-2 and the high activity for water oxidation is maintained for over 30 h. Impressively, the performance of the as-fabricated composite photoanode for PEC water splitting can be further enhanced through incorporating a certain amount of Co^2＋ cation into NiFe-LDH as OEC. The photocurrent density is achieved up to 4.45 mA cm^-2 at 1.23 V vs. RHE. This value is the highest yet reported for un-doped BiVO4-based photoanodes so far.

Aluminium nanohole arrays enhanced resonance Raman scattering spectra in the near ultraviolet region

Aluminium nanohole arrays with fixed diameter were fabricated by focused ion beam and the periodicities were turned.Aluminium nanohole arrays enhanced resonance Raman scattering spectra in the near ultraviolet region were studied experimentally and theoretically,which revealed that the SERRS enhancement factor was as high as 6 orders.