Self-assembled monolayers (SAMs) have been widely used in studying interfacial phenomena, biological processes, electrochemistry, photoelectrochemistry, photoactivity and molecular interaction. Much research has been carried out in fabricating and removing SAMs on different substrates. In this work, we report for the first time, to our knowledge, that SAMs of thiolates on gold can be removed by immersing SAMs in 0.5 M NaBH 4 solution for 10 min. The procedure of removing thiolates was very convenient. Cyclic voltammetry, surface-enhanced Raman spectroscopy, and X-ray photoelectron spectroscopy were used to characterize this process. The results indicated that the SAMs of thiolates on gold can be removed efficiently by NaBH 4.

Optimization of solid-state lighting spectra is performed to achieve beneficial and tunable circadian effects. First, the minimum spectral circadian action factor (CAF) of 2700 K white light-emitting diodes (LEDs) is studied for applications where biologically active illumination is undesirable. It is found that white-LEDs based on (i) RGB chips, (ii) blue & red chips plus green phosphor, and (iii) blue chip plus green & red phosphors are the corresponding minimum-CAF solutions at color-rendering index (CRI) requirements of 80, 90, and 95, respectively. Second, maximum CAF tunability of LED clusters is studied for dynamic daylighting applications. A dichromatic phosphor-converted blue-centered LED, a dichromatic phosphor-converted green-centered LED, and a monochromatic red LED are grouped to obtain white spectra between 2700 K and 6500 K. A maximum CAF tunability of 3.25 times is achieved with CRI above 90 and luminous efficacy of radiation of 313 - 373 lm/W. We show that our approaches have advantages over previously reported solutions on system simplicity, minimum achievable CAF value, CAF tunability range, and light source efficacy.

Recently, natural biomass has been widely explored as a precursor to prepare carbon materials due to its abundant, low-cost, and renewable character. Herein, a series of high-performance heteroatom-doped carbons hase been successfully produced from natural biomass small molecular peach gum for the first time. The sheet-like O-doped carbons PG-C and HTC-PG-C are synthesized by pyrolyzing peach gum (PG) and hydrothermally treated peach gum (HTC-PG), respectively. The three-dimensional hierarchical porous O-doped carbons PG-AC, HTC-PG-AC, and N/O-codoped carbon HTC-NPG-AC are prepared via KOH activation of PG, HTC-PG, and a hydrothermally treated mixture of peach gum and 1,6-hexanediamine (HTC-NPG), respectively. The PG-C, HTC-PG-C, PG-AC, HTC-PG-AC, and HTC-NPG-AC possess specific surface areas of 274.3, 374.3, 1256, 1279, and 1535 m 2 g −1 , respectively. In particular, PG-C, HTC-PG-C, PG-AC, HTC-PG-AC, and HTC-NPG-AC exhibit excellent capacitances of 199, 223, 334, 322, and 406 F g −1 at 0.2 A g −1 in 6 M KOH and high rate capabilities of 61.4%, 72.3%, 65.6%, 73.1%, and 76.2% from current densities from 1.0 to 20.0 A g −1 , respectively. Moreover, the PG-C-assembled symmetric supercapacitor displays an energy density of 9.38 W h kg −1 at a power density of 375 W kg −1 in 6 M KOH electrolyte, while the HTC-PG-C-, PG-AC-, HTC-PG-AC-, and HTC-NPG-AC-assembled supercapacitors exhibit high energy densities of 14.66, 16.09, 18.04, and 22.84 W h kg −1 at 400 W kg −1 , respectively. Additionally, using 1 M Na 2 SO 4 as electrolyte, the PG-C-, HTC-PG-C-, PG-AC-, HTC-PG-AC-, and HTC-NPG-AC-assembled supercapacitors deliver outstanding energy densities of 11. 25, 16.94, 19.31, 20.83, and 25.56 W h kg −1 at 500 W kg −1 , respectively. The strategy to utilize cost-effective renewable biomass small molecule peach gum as precursor to achieve large-scale repeatable production of heteroatom-doping carbons is promising. The peach gum-based heteroatom-doped carbons are prominent electrode materials for high-performance supercapacitor applications.

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