Water State-Driven Catalytic Hydrolysis of Ammonia Borane on Cu3P-Carbon Dot-Cu Composite

Photothermally-activated suspended aerogel triggers a biphasic interface reaction for high-efficiency and additive-free hydrogen generation

The need for a sustainable hydrogen supply has sparked significant efforts to develop effective liquid hydrogen carriers with high hydrogen content that can be safely stored and undergo controlled hydrogen release. However, a major challenge lies in the ultralow hydrogen evolution rate caused by the direct dehydrogenation of liquid hydrogen carriers. Conventionally, accelerant additives are employed to improve the dehydrogenation rate, but this strategy inevitably sacrifices the hydrogen storage density. Therefore, achieving high-efficiency hydrogen release and high storage density remains a daunting task. Herein, we develop an innovative photothermally-activated suspended biphasic reaction strategy, which absorbs solar radiation and re-radiates infrared photons to induce photothermal evaporation and in situ dehydrogenation of liquid hydrogen carriers, fundamentally circumventing the employment of additives. Furthermore, by leveraging this phase transition-induced biphasic reaction design, the strategy improves the required reaction temperature and drastically lowers hydrogen transport resistance. Therefore, an impressive hydrogen evolution rate of 386 mmol g-1 h-1 is achieved from pure formic acid with an ultrahigh hydrogen storage density of 53 g L-1, representing a threefold improvement in rate compared to state-of-the-art strategies. Our approach introduces a fresh perspective for the dehydrogenation of liquid hydrogen carriers, encompassing formic acid, hydrazine hydrate, and so on, and concurrently guarantees exceptional hydrogen release capabilities and excellent hydrogen storage density.

Electron Tandem Transport Channel in a Cu3P/Sv-ZnIn2S4 p-n Heterojunction for Photothermal-Photocatalytic Benzyl Alcohol Oxidation and H2 Production

The development of photocatalytic systems with an electron tandem transport channel represents a promising avenue for improving the utilization of photogenerated electrons and holes despite encountering significant challenges. In this study, ZnIn2S4 (Sv-ZIS) with sulfur vacancies was fabricated using a solvothermal technique to create defect energy levels. Subsequently, Cu3P nanoparticles were coupled onto the surface of Sv-ZIS, forming a Cu3P/Sv-ZIS p-n heterojunction with an electron tandem transport channel. Experimental findings demonstrated that this tandem transport channel enhanced the carrier lifetime and separation efficiency. In addition, mechanistic investigations unveiled the formation of a robust built-in electric field (BEF) at the interface between Cu3P and Sv-ZIS, providing a driving force for electron migration. The combined consequences of the transport channel, the strong BEF, and photothermal effect led to a surface carrier separation efficiency of 65.85%. Consequently, Cu3P/Sv-ZIS achieved simultaneous H2 yield and benzaldehyde production rates of 18,101.4 and 15,012.6 μmol·g-1·h-1, which were 2.31 and 2.62 times higher than those of ZnIn2S4, respectively. This work exemplifies the design of the p-n heterojunction for the efficient utilization of photogenerated electrons and holes.

Polyelectrolyte Hydrogel-Functionalized Photothermal Sponge Enables Simultaneously Continuous Solar Desalination and Electricity Generation Without Salt Accumulation

Technologies that can simultaneously generate electricity and desalinate seawater are highly attractive and required to meet the increasing global demand for power and clean water. Here, a bifunctional solar evaporator that features continuous electric generation in seawater without salt accumulation is developed by rational design of polyelectrolyte hydrogel-functionalized photothermal sponge. This evaporator not only exhibits an unprecedentedly high water evaporation rate of 3.53 kg m-2 h-1along with 98.6% solar energy conversion efficiency but can also uninterruptedly deliver a voltage output of 0.972 V and a current density of 172.38 µA cm-2 in high-concentration brine over a prolonged period under one sun irradiation. Many common electronic devices can be driven by simply connecting evaporator units in series or in parallel without any other auxiliaries. Different from the previously proposed power generation mechanism, this study reveals that the water-enabled proton concentration fields in intermediate water region can also induce an additional ion electric field in free water region containing solute, to further enhance electricity output. Given the low-cost materials, simple self-regeneration design, scalable fabrication processes, and stable performance, this work offers a promising strategy for addressing the shortages of clean water and sustainable electricity.

Boosting the Catalytic Performance of NiMoO4 Nanorods in H2 Generation upon NH3BH3 Hydrolysis via a Reduction Process

Although a range of noble metal catalysts, including Ru, Rh, Pd, Pt, and Au, have been developed for efficient H2 generation upon NH3BH3 hydrolysis at room temperature, this is a highly urgent need for exploring earth-abundant metal nanocatalysts for H2 generation upon NH3BH3 hydrolysis. Herein, a NaBH4 reduction strategy was developed to boost the catalytic performance of NiMoO4 nanorods in H2 generation upon NH3BH3 hydrolysis. Indeed, the pristine NiMoO4 nanorods were catalytically inert in NH3BH3 hydrolysis. Significantly, the reduced NiMoO4 nanorods presented excellent catalytic activity in H2 generation upon NH3BH3 hydrolysis, with a turnover frequency (TOF) of 31.2 L(H2)·gcat-1·h-1. Interestingly, the TOF of NH3BH3 hydrolysis over reduced NiMoO4 nanorods significantly increased from 31.2 to 53.6 L(H2)·gcat-1·h-1 under 0.3 M NaOH. The boosting catalytic performance of NiMoO4 nanorods via NaBH4 reduction in H2 generation might be attributed to the higher content of Oads and the formation of nickel boride in the reduced NiMoO4 nanorods. In this work, NH3BH3 hydrolysis over reduced NiMoO4 nanorods was not only used for safe H2 generation but also for its in situ tandem hydrogenation in organic chemistry.