Ding R G, Lu G Q, Yan Z F, Wilson M A
Department of Chemical Engineering, University of Queensland, Brisbane, Queensland, 4072, Australia.
J Nanosci Nanotechnol. 2001 Mar;1(1):7-29. doi: 10.1166/jnn.2001.012.
Recent progress in the production, purification, and experimental and theoretical investigations of carbon nanotubes for hydrogen storage are reviewed. From the industrial point of view, the chemical vapor deposition process has shown advantages over laser ablation and electric-arc-discharge methods. The ultimate goal in nanotube synthesis should be to gain control over geometrical aspects of nanotubes, such as location and orientation, and the atomic structure of nanotubes, including helicity and diameter. There is currently no effective and simple purification procedure that fulfills all requirements for processing carbon nanotubes. Purification is still the bottleneck for technical applications, especially where large amounts of material are required. Although the alkalimetal-doped carbon nanotubes showed high H2 weight uptake, further investigations indicated that some of this uptake was due to water rather than hydrogen. This discovery indicates a potential source of error in evaluation of the storage capacity of doped carbon nanotubes. Nevertheless, currently available single-wall nanotubes yield a hydrogen uptake value near 4 wt% under moderate pressure and room temperature. A further 50% increase is needed to meet U.S. Department of Energy targets for commercial exploitation. Meeting this target will require combining experimental and theoretical efforts to achieve a full understanding of the adsorption process, so that the uptake can be rationally optimized to commercially attractive levels. Large-scale production and purification of carbon nanotubes and remarkable improvement of H2 storage capacity in carbon nanotubes represent significant technological and theoretical challenges in the years to come.
本文综述了碳纳米管在储氢方面的生产、纯化以及实验和理论研究的最新进展。从工业角度来看，化学气相沉积法已显示出优于激光烧蚀法和电弧放电法的优势。纳米管合成的最终目标应该是能够控制纳米管的几何参数，如位置和取向，以及纳米管的原子结构，包括螺旋度和直径。目前还没有一种有效且简单的纯化方法能满足处理碳纳米管的所有要求。纯化仍然是技术应用的瓶颈，尤其是在需要大量材料的情况下。尽管碱金属掺杂的碳纳米管显示出较高的氢重量吸收量，但进一步研究表明，其中部分吸收是由于水而非氢气所致。这一发现表明在评估掺杂碳纳米管的储存容量时存在潜在的误差来源。然而，目前可用的单壁纳米管在中等压力和室温下的氢吸收值接近4 wt%。要达到美国能源部的商业开发目标，还需要再提高50%。实现这一目标需要将实验和理论研究相结合，以全面了解吸附过程，从而能够合理地将吸收量优化到具有商业吸引力的水平。未来几年，碳纳米管的大规模生产和纯化以及碳纳米管储氢容量的显著提高将是重大的技术和理论挑战。
