在前段时间论文被某老师点出来我的BET表征的比表面积数据应该只保留整数位，而不应该保留小数位。也就是比如你BET测的比表面积为1234.56 m2/g，则在论文中应该写为1234 m2/g，而非1234.56或1234.6。我当时就纳闷了，我BET表征数据直接给我的就是1234.56 m2/g，最多按照仪器最后一位估读不准舍弃，而为什么需要舍弃全部小数位？
说实话，我现在都没明白为何如此，网上也没找到具体保留的规则。对此，我将基于文献检索结果与个人推测，分析部分表征测试的有效数字保留情况，给大家一定的参考（不一定全对，但至少代表这是大佬们的默认规则）。个人理解红外和XPS是和标准图谱有效保留数字一致，而BET则摸不着头脑。
如果有懂这背后确切原因的朋友，欢迎私信或者留言告知，不胜感激！
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比如1234 m2/g，而非数据报告中的小数点后两位或四位。
数据报告实例
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检索方式：Ang、JACS等期刊直接搜“Specific surface area”，每个期刊搜索页面随机打开10篇，共计20篇进行统计，其中100%符合该规则。以下仅展示其中5篇：
例1
https://doi.org/10.1002/anie.201913719
The optimized ZIF-8/AG-CA exhibits low density (24 mg cm−3), high specific surface area (516 m2 g−1), and large hierarchical pore volume (0.58 cm−3 g−1), and it shows outstanding performance for the adsorption of various organic pollutants.
例2
https://doi.org/10.1002/anie.202011260
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例3
https://doi.org/10.1002/anie.202102665
With octahedral TiIV complex as the building unit, this study reports on the first 3D anionic titanium-based COF (Ti-COF-1) with an edge-transitive (6, 4)-connected soc topology. Ti-COF-1 exhibits high crystallinity, superior stability, and large specific surface area (1000.4 m2 g−1).
例4
https://doi.org/10.1021/jacs.3c04995
The total specific surface area of CP@1-2 was further determined to be 735 m2·g–1 using the Brunauer–Emmett–Teller (BET) model fit (Figure S9), lower than the 962 m2·g–1 of the [TAPB-BTCA] COF (Figure S8). This could be attributed to the existence of the amorphous [TAPB-PDA] component in CP@1-2. The surface area and pore volume contributed by micropores could be further calculated using the t-plot method, which account for 491 m2·g–1 and 0.21 cm3·g–1, respectively. Thus, the external surface area and pore volume contributed by non-micropores (including meso-, macro-, and non-pores) are about 244 m2·g–1 (∼33% of the total surface area) and 0.67 cm3·g–1, much higher than the 148 m2·g–1 (∼15%) and 0.27 cm3·g–1 of the [TAPB-BTCA] COF, respectively (see the pore size distribution in Figure S9 and t-plot method in Figure S10).
例5
https://doi.org/10.1021/jacs.7b05025
Furthermore, the 2DP film also showed a Brunauer–Emmett–Teller (BET) surface area of 102 m2 g–1 (Figure 4b), nearly 1 order of magnitude higher than graphene oxide paper (11 cm2 g–1, Figure S16) probably due to its in-plane porosity of 2DP and interlayer porosity between 2DP sheets (inset in Figure 4b).
比如1234 cm-1，而非数据报告中的小数点后两位。
数据报告实例
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检索方式：Ang、JACS等期刊直接搜“FT-IR”，每个期刊搜索页面随机打开10篇发表日期较近的，共计20篇进行统计，其中100%符合该规则。以下仅展示其中5篇：
例1
https://doi.org/10.1002/anie.202410246
Zr(OH)4 exhibited a signal indicative of phenylacetylene adsorption, with a characteristic peak at 2109 cm−1 attributed to the stretching vibration of the C≡C bond in phenylacetylene. Additionally, the peaks at 1440 cm−1 and 1490 cm−1 originated from the stretching vibration of benzene ring. In contrast, the infrared adsorption curve of styrene shows weak benzene ring adsorption peaks (1440 cm−1 and 1490 cm−1) and C=C group (≈1630 cm−1), indicating weak adsorption of styrene on the Zr(OH)4.
例2
https://doi.org/10.1002/anie.202412334
Note that the characteristic peaks of C=O and C−S for BTT-ICTO are located near 1700 and 1470 cm−1, respectively. The two characteristic peaks gradually weaken along the discharge process.51 It can be observed that the intensity of the characteristic peak for C=O exhibited an expeditious decay from 3.6 to 1.8 V and tends to stabilize at 1.8–1.0 V. The C−O characteristic peak close to 1070 cm−1 showed the opposite trend, which revealed the existence of coordination between Li+ and C=O functional groups.
例3
https://doi.org/10.1002/anie.202407182
In FT-IR spectra, LF5 exhibits the peaks at 1721 and 1667 cm−1 assigned as the stretching vibration of carbonyl groups (Figure 2b). Upon increasing content of SSPy, the two bands of 1721 cm−1 slightly red-shifted to 1717 cm−1, while the band at 1667 cm−1 corresponding to the amide-I blue-shifted to 1699 cm−1 gradually.
例4
https://doi.org/10.1021/jacs.4c08517
In fact, the IR-spectra of the samples exposed to CO show a significant red-shift and broadening of the spectroscopic features, when comparing PtxFey@SiO2 to Pt@SiO2, further supporting Pt–Fe alloy formation (Figure S20–S26). The occurrence of pressure-dependent features at 2005 and 2025 cm–1 hints toward the formation of a Fex(CO)y species, therefore indicating the presence of reduced iron. (30) The extent of the red-shift and the amount of Fex(CO)y species increases with increasing Fe-content (Figure S28) and is affected by temperature. (30)
例5
https://doi.org/10.1021/jacs.4c05192
The FT-IR spectra captured at discharge voltages of 1.3, 1.0, 0.6, and 0.2 V revealed a progressive fading of the amide carbonyl (C═O) and N–H stretching frequencies, typically found at 1633 and 3300 cm–1, respectively (Figure 6b).
比如456.7 eV而非数据报告中的小数点后两位。
数据报告实例
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检索方式：Ang、JACS等期刊直接搜“XPS”，每个期刊搜索页面随机打开10篇，共计20篇进行统计，其中100%符合该规则。以下仅展示其中5篇：
例1
https://doi.org/10.1002/anie.202405983
In the case of the pristine TPPA, the O 1s peak (Figure 2c) can be fitted with two components with binding energies (BE) of 532.0 eV and 533.3 eV in a 2 : 1 ratio, as expected for the two chemically different oxygen atoms in the anhydride group.
例2
https://doi.org/10.1002/anie.202403022
In the X-ray photoelectron spectroscopy (XPS) survey spectrum shown in Figure 1D, binding energy peaks for C 1s, S 2p, and Cd 3d are detected. The high-resolution spectrum of C 1s in Figure 1E reveals the presence of C=O bonds (288.2 eV), C−N bonds (285.9 eV), and C−C bonds (284.8 eV). These findings reveal the functional groups in rGO, where the presence of C=O and C−N bonds indicates incomplete deoxygenation of graphene oxide during the reduction process, while the presence of C−C bonds characterizes the graphene structure in the material.
例3
https://doi.org/10.1002/anie.202404660
X-ray photoelectron spectroscopy (XPS) analysis of 30 % W/Z revealed the presence of W, O, Zn, In, and S (Figure S4). The binding energies at 34.3, and 36.2 eV corresponded to W5+, while those at 35.5 and 37.6 eV were related to W6+ in W18O49.
例4
https://doi.org/10.1021/jacs.4c01897
The modal peak position of 284.3 eV is at a slightly lower value than the experimental 284.5 eV, which is expected due to a lack of CEBE shifts from high oxygen content seen in the other samples.
例5
https://doi.org/10.1021/jacs.3c10892
The Cu 2p3/2 XP spectrum displays a main intensity peak at ∼932.5 eV and a low-intensity satellite peak at +13 eV from the main photoionization peak, indicative of Cu(I) (Figure 1C). (9,59,60) The Cu(I) LMM Auger signal shows a kinetic energy of 916.6 eV, commensurate with Cu2O, and the valence band spectrum contains a peak position and shape that is also diagnostic of Cu2O (Figures S21 and S22).
以上仅是个人搜索整理得出来的结果，不意味这只有以上3种仪器表征数据与论文写作中有效数字保留不同。如对其它表征数据有疑问，可以自己搜索验证。
而在环境领域，以上默认规则就仿佛失效了…
比如环境领域顶刊
1.Environ. Sci. Technol. 2024, 58, 6, 3007–3018
In addition, compared with the 3D catalyst (SSA 287.45 m2·g–1; Figure S3), the apparently decreased SSA (35.78 m2·g–1) for 2D-Co/CAFE40 was mainly due to the expanded pore range from the meso-level to the macrolevel, the emergence of microchannels, and the elimination of the abundant porous deep-inner structure.2.Environ. Sci. Technol. 2024, 58, 1, 660–670
The specific surface area of Cu-BDC-2D is 67.327 m2/g, which is similar to that reported in previous literature. (34) The specific surface area of CuS-BDC-2D is reduced to 35.541 m2/g compared with Cu-BDC-2, which could be attributed to sulfur adhesion.
The orbital peaks of Hg 4f in Figure 7b were 104.44 and 100.33 eV, respectively, which were typical peaks of HgS, indicating that the main product of the reaction was HgS. Additionally, the S 2p peak of CuS-BDC-2D was deconvoluted into five subsignals, i.e., saturated sulfide (S2–, 161.39 and 162.29 eV), disulfide (S22–, 163.36 eV), and polysulfide (Sx2–, 164.25 and 165.25 eV). The characteristic peak of SO42– was at approximately 168.47 eV.3.Environ. Sci. Technol. 2024, 58, 42, 18915–18927
Finally (88 days), the PLA specific surface area increased approximately 13-fold (26.9977–387.3206 m2·g–1).4.Environ. Sci. Technol. 2024, 58, 7, 3540–3551
The result was attributed to the large specific surface area (945.04 m2/g) and certain content AAEMs such as 1.09 wt % of K and 0.48 wt % of Mg (Figure 1d,e and Table S3).The Ni3Fe alloy (2θ = 44.22°), (24,42) Ni–Co alloy (2θ = 44.40°) (43), and NiO–MgO solid solution (2θ = 43.15°–43.26°) (38) were also obtained, as shown in Figure 1c.
以上仅代表个人搜索过程中的结果，不代表任何意见。
以上就是这期的主要内容，感谢观看！如果觉得有帮助，可以关注、点赞、转发。期待下期再见！
