Abstract：
Efficient photocatalytic solar CO2 reduction presents a challenge because visible-to-near-infrared (NIR) low-energy photons account for over 50% of solar energy. Consequently, they are unable to instigate the high-energy reaction necessary for dissociating C═O bonds in CO2. In this study, we present a novel methodology leveraging the often-underutilized photo-to-thermal (PTT) conversion. Our unique two-dimensional (2D) carbon layer-embedded Mo2C (Mo2C-Cx) MXene catalyst in black color showcases superior near-infrared (NIR) light absorption. This enables the efficient utilization of low-energy photons via the PTT conversion mechanism, thereby dramatically enhancing the rate of CO2 photoreduction. Under concentrated sunlight, the optimal Mo2C-C0.5 catalyst achieves CO2 reduction reaction rates of 12000-15000 μmol·g-1·h-1 to CO and 1000-3200 μmol·g-1·h-1 to CH4. Notably, the catalyst delivers solar-to-carbon fuel (STF) conversion efficiencies between 0.0108% to 0.0143% and the STFavg = 0.0123%, the highest recorded values under natural sunlight conditions. This innovative approach accentuates the exploitation of low-frequency, low-energy photons for the enhancement of photocatalytic CO2 reduction.
摘要：
有效的光催化太阳能CO2还原提出了挑战，因为可见光到近红外（NIR）低能光子占太阳能的50％以上。因此,它们不能引发在CO2中解离C=O键所需的高能反应。在这项研究中,我们提出了一种利用经常未充分利用的光热（PTT）转换的新颖方法。我们独特的二维（2D）碳层嵌入的Mo2C（Mo2C-Cx）MXene催化剂在黑色中展示了优异的近红外（NIR）光吸收。这使得能够通过PTT转换机制有效利用低能光子，从而显著提高CO2光还原的速率。在集中的阳光下，最佳Mo2C-C0.5催化剂对CO的CO2还原反应速率为12000-15000μmol·g-1·h-1，对CH4的CO2还原反应速率为1000-3200μmol·g-1·h-1。值得注意的是,催化剂提供太阳能到碳燃料（STF）的转换效率在0.0108％至0.0143%之间，STFavg=0.0123%，自然阳光条件下的最高记录值。这种创新的方法强调了低频的开发，低能光子用于增强光催化CO2还原。
